I’m always bugged more by individual moments than bigger things. So while T’Pol might be wearing an old fun center carpet as a uniform, and the temporal Cold War is both overly complex and excruciatingly boring neither of those things bothers me more than the following.
In season one, there is an episode titled ‘Unexpected’. In this episode Tripp becomes space pregnant from an alien space mama. During his pregnancy he is framed as becoming irrationally overconcerned about the safety of very minor or unlikely hazards.
At one point, he is in engineering and complains that if you hold onto the handrail of the elevator while it moves, your fingers will be sliced off against the scaffolding since there is no gap.
A crew member brushes him off by just saying, essentially, “Lol skill issue, just don’t hold the handguard.”
Again, Tripp is the one being framed as irrational in this discussion. Because he has a problem with a handguard that slices your fingers off.
Space hormones or not, he’s right that it’s a terrible design.
Replicators convert matter into other matter. In Voyager, they show that replicators use a blue gel, and that blue gel is impossible to make on the ship. It’s why Neelix needs to make a mess hall and cook. It’s probably cheaper to make parts out of metal than produce the gel, and there might be limits to the size of what can be made. Also, there are materials replicators can’t make, such as Latinum, the currency that Ferengi’s use. It does seem odd that replicators make both the tea and the tea cup. Seems like a waste to make the cup too. Then what happens to the cup?
The Enterprise D from TNG is not meant to be a warship and there are a couple episodes that explore that. But, would you rather have your exploration vessel be able to defend itself if needed, or not?
The Federation does trade with the other empires as well as manage production within itself, but it handles trade at the government level, so that individuals don’t need to worry about it. Some still do trade though.