You are right, but also wrong. They cant replicate complicated things, but they can replicate parts of complicated things, and then professionals can assemble them. They reference it a few times. They talk about it when they need a new energy source because they are short on supplies, more than just food is mentioned. That and the delta flyer. They assemble to a degree but parts are replicated and assembled. Otherwise they would care about a lot more things than just energy and fuel in the delta quadrant. I think there are a few things that don’t qualify, like the warp coils for the entire starship. But even then they can make shitty coils for shuttles I’m pretty sure.
I may be crazy but I feel like there’s a scene in enterprise where they are getting repaired at a Starbase and they show a panel get like replicated/transported to place and then it’s bolted or welded in after. They do mention that replicators and transporters are almost the exact same a few times so it’s hard to tell.
God damnit it’s kinda embarrassing how much I know about Star Trek. I use the show as a coping mechanism lol.
Edit: oh shit gel packs too, they couldn’t replicate new gel packs.