I’ve got two very cheap carbon frames (hardtail and gravel) from Chinese companies, both have been absolutely fine. The Chinese companies also have brand names and reputations to loose, if you look to buy from one that’s established and going for a while, I think you’ll be fine.
I do think you need to know a bit about the frame you want - geometry, parts compatability, and plan to build it up yourself preferably. I wouldn’t just buy any frame you like the look of, and drop it at a bike shop and expect them to figure out how to put the groupset of your choice on it.
I don’t know about warrenty, it’s not a factor I think about much when buying things I’m likely to use and break, but the companies I bought from were easy to deal with and reliable during the buying process.