Oh, there's so much to unpack here...
1. New production, new look. As ever.
2. Quite some time has passed, so need to visually define a new era.
3. Also need to visually define the intermediate "flashback" era too
-- and it has to look *different* to both the "old" costumes (TNG movies / DS9) and the "new" PIC costumes.
4. A need to maintain some sort of continuity with previous iterations through both of these.
5. Starfleet is not the main focus of this show -- so seems unlikely we will routinely see main cast in these.
6. Design needed to be simple and easily (cheaply) reproducible, given the large number of extras in the SFHQ shots.
7. Because they can...
The basic premise of retaining the three defined branch-of-service colors from the TNG / DS9 / VOY / TNG movies seems reasonable. So does the basic visual theme of maintaining the shoulder yoke motif and black as the base color.
As far as that goes, I have no real problem with the broad approach to the new designs. I don't mind the new combadge; it's not what I would necessarily have done and I think the visual cue to the DSC badge design is unnecessary but they seem determined to include it so, meh, whatever. Overall, it seems reasonable to update the design (and they are still using the previous version at the time of the flashbacks) and I don't mind that it's *not* exactly the same as the AGT / Endgame design. Those were, after all, only *potential* futures at that point so perhaps no surprise that things didn't turn out *exactly* that way.
What does bug me though, is the way the new uniform just seems to have been thrown together. Part of the reason for the FC redesign of the DS9 utility jumpsuits was that it was painfully obvious just how boring and bland the DS9/VOY jumpsuits looked on the big screen -- hence the added detail of the padded/quilted shoulders and the colored cuff-bands, etc. The same is true now given that much bigger TV screens are far more common and everything is shot in HD.
With this in mind, the "new" Starfleet uniform seems just a bit too bland: black pants and boots, black body and sleeves, plain black undershirt, colored yoke and collar. That's it. They've added a couple of design tweaks, such as the squared-off ends on the sleeve points and a similar feature for the notch at the front of the yoke but there's very little else. For the casual viewer it's just TOO much like the old DS9 / VOY jumpsuit and they simply won't see the difference.
Putting the rank insignia on the colored yoke rather than on the black *below* the yoke also seems kinda dumb. I have a good idea why that happened as it's where the pips were on the TNG / DS9 / VOY dress uniforms and the AGT / Endgame uniforms used a similar placement but the insignia would have been so much more visible on the new uniforms if they had just been moved down and inch or so onto the black, just below the yoke, level with the top of the combadge. Oh well; again, meh, whatever. What *is* a shame is that the fit and finish looks dreadful -- like the worst examples of fan cosplay at conventions appearing on screen (!).
I haven't yet seen any of this on-screen, so will reserve final judgment until I can see the episodes, but I see no need for it to be quite so different to the rest of the uniforms. If there had been other folks walking around amongst the extras wearing grey jackets with black shoulders and colored undershirts then I could believe that this was a more formal version, something akin to what the late-season TNG uniform was, relative to the DS9 utility uniform but in isolation it makes little sense. The trend with late-season TNG / DS9 was for the flag officer uniforms to look much more like the standard duty uniforms with only minor changes, rather than the markedly different uniforms from early TNG. Even DSC managed to stick to the same basic design with just the different badge and the additional shoulder detail.
I guess the key point is that Starfleet and the Federation is largely the backdrop to this series rather than front-and-center in the foreground. In that respect, it doesn't really matter what they do as long as there are enough visual cues from the previous eras for the broad majority of the audience to recognise that, OK, yeah, those guys over there are Starfleet.
