Many people were "complaining" (not only in STO) that Starfleets uniforms always looked like they didn't offer any protection from anything, something I do agree on. Often I thought wouldn't it be sensible to have some kind of "jacket" at least to wear on away missions, let alone tactical engagements?
Then came STO and I think the "plastic" looking uniforms are kinda meant to be "more protective", like the prototype combat suits featured in DS9s "Siege of AR-558". Whenever I see them, I think that it's just a more "protective" version of the uniform. It's still ugly but that's kinda explains it.
The "antares 2" pattern the NPC security wears (which now patrol ESD with drawn miniguns, btw...) was always something like the "hazard suit" from Elite Force in my eyes.
In my own little STO canon, my senior officers wear the last canon uniform (the TNG movie/late DS9 one). My junior officers/regular crewmen up until 1st Lt. wear the DS9 uniform in late DS9 color pattern, effectively a simpler version of it also lacking the sleeve stripes. Those Antares-Security guards are "tactical offiers" in my little world, rsembling the "hazard suit" from mentioned games since these kinda make sense as a "armour" fitting the overall style.
This way, I kind of explain away minor things that bug me. Can't fix the game, though
To be fair TNG uniforms have some kind of nanotechnology at work in them. They unzip with no zippers or buttons and probably have other properties. I always thought it didn't make sense when they visit other worlds without breath masks since many episodes have character getting infected with space diseases or mutated by them.