This post is long.
TL;DR: summoner is the worst in terms of dps, mage has decent dps but has problems with mana, melee does the most dps in certain circumstances, and ranger consistently has high dps in virtually any situation
Notes: I edited the fuck out of this in the last 2 hours, because I tested all the classes right after I posted this in order to validate my purported claims. Also, the max dps values I post here are based off of stat bonuses from buffs including nebula damage boost, feral bite, and wet truffle.
Summoner does the least dps out of all the classes now, especially since they changed a summoning mechanic. Previously in 1.3, the damage modifier affecting a minion was determined by the accessories present when that particular minion is summoned; and as a result, if a minion was summoned with a summoning emblem and that emblem is removed, that minion would still retain the damage boost from that emblem. However, this was changed in 1.4, and now minion damage is dependent on the modifiers currently present at all times. This is very unfortunate, because from testing, summoning damage is quite lame, barely above a consistent 10k dps with a stardust dragon with the stardust guardian on different single hitbox targets (various bosses). Additionally, terriaprisma, although having one of the smartest minion ai in the game, does a lame amount of end game damage, doing less than 10k damage with the stardust guardian (a number also derived from numerous tests on different single hitbox bosses). Furthermore, the stardust dragon has a horrible ai and fails to consistently place its segments on nimble bosses, so terraprisma would probably be used in more circumstances. Again, the terraprisma has a lame dps, but atleast it requires no aim and actually has a smart enough ai that can consistently hit bosses over a decent range that extends off-screen. Summoner was the most troubling class to test. The target dummy has 0 defense, and the only way I could fairly test the dps of summoning weapons was on bosses with single targets with low defense. Note that the summoner class was not judged fairly compared to the others, neverthless, it was not a spectacular class.
Mage seems to be the same as always, similar to when it was in 1.3. It is still an annoying class to play, and sadly with the buffs to the lategame melee and ranger classes, mage seems to be worse off now. Mana sickness is a horrible debuff, dramatically decreasing damage output, and the only way to counter this is by avoiding the usage of mana potions in lieu of a constant source of mana stars. The most powerful magic weapon, the last prism, constantly drains an exorbitant amount of mana, demanding a constant heavy stream of mana. With this annoying difficulty, the last prism can get up to 26k dps on a single target dummy. The lunar flare also has similar problems to the last prism, although it does less damage on a single target dummy, doing 16k dps. Both the lunar flare and last prism are also not the easiest to aim. The former requires timing and has a limited on-screen range while the latter must be slowly tilted if you want to angle and aim the weapon at the boss. Anyway, the player usually must remain static to supply themselves with a constant source of mana stars, so when the player is actually mobile, they must use mana potions in order to supply their last prism. Doing this, the player only does a little under 15k dps with the last prism.
Melee has the most damage output, and on a single target dummy, the zenith can do just about 47k dps. As some of you may know from Mappy’s video, this depends on positioning relative to the target dummy. Depending on how you aim the zenith, you do a certain amount of damage. Moreover, positioned with your back facing the target dummy, you can do the the aforementioned 47k dps (although this is probably not practical in the setting of a real boss fight). In my own testing, there are numerous variables to consider while using the zenith (including the position of the mouse relative to the target dummy and the distance away from the target dummy), and the most amount of damage I could reach with a target dummy in front of me was about 30k dps. Mappy also showcased the Zenith’s infinite range, but this is only horizontal range. Furthermore, it requires the usage of numerous monitors. It would probably not be practical to apply the zenith’s infinite range in an actual boss fight practically. In a setting when the player is mobile, the zenith would probably just do over 10k dps and maybe 20k dps sometimes. Doing this, the zenith also only has a range which would be limited to the player’s own screen, but atleast the hitbox of the zenith is so large it requires little thought into aiming or timing.
Ranger probably is the way to go in terms of dps. It has a consistently high dps coupled with a large range and easy to aim projectiles. Like in 1.3, I still think the ranger class reigns supreme in terms of practical dps. The invisibility function of the vortex armor must be used of course in order to achieve max damage, and an already vulnerable ranger is forced to be crippled in terms of locomotion. However, the ranger class now has an available option that no other classes have. All the other classes which I have previously mentioned must utilize damage and crit affecting accessories in all seven accessory slots. However, doing this with the ranger, you actually have an extra free 7th slot for use if you try to maximize ranger damage (unless you utilize the phantasm, in which you would use a magic quiver or any other variant). That extra 7th slot opens up many new possibilities, and personally, I would use any form of wings, especially the new celestial starboard, in order to counter the crippling affects of the slowness induced by the invisibility function of the vortex armor. Anyway, the S.D.M.G. with luminite bullets does about 14k dps on a single target dummy, and it can do about 15k dps with crystal bullets on a single target dummy. The S.D.M.G. does require some aiming, however it has a great range that extends off-screen. Surprisingly, the phantasm is more effective than the S.D.M.G. with luminite arrows, doing about 20k dps on a single target dummy and having very good pierce. With luminite arrows, the phantasm also has a great off-screen range like the S.D.M.G., but the arrows do have a curved trajectory which does limit the range. Unlike the S.D.M.G., the phantasm with luminite arrows covers a large area of the screen, making it very easy to aim. Nevertheless, the extra 7th slot I have mentioned earlier would be used for a magical quiver, or any equivalent, in order to achieve this much damage. Despite this, even if the 7th free slot is not used for a magical quiver, the phantasm still does about 19k dps which is still a lot. The celebration mk2 is able to do over 20k dps on a single target, only held back by its somewhat limited range which barely goes offscreen (the rocket projectiles that are affected by gravity). Like the phantasm, the projectiles do atleast cover a large area of the screen, so it is easy to aim. One problem with the celebration mk2 is that the rocket it produces are very inconsistent. They have varying trajectories, and hit the target invariably. If you are farther away, the celebration mk2 may do under 10k dps, a pitiful dps, however, if you are close and every shot connects, up to 20k dps can be done.