Not sure how to say this nicely, but if you rely on an AI so much for programming, maybe you are doing something horribly wrong.
Unless youre writing, say, Zig, LSP (e.g. native LSP with Mason, or coc-nvim) will give you as good of an autocomplete as you can get.
That's not true, Copilot can complete a whole function based on a comment by understanding the intent behind it, no LSP server can do that. On the other hand, Copilot can't do the kind of code analysis that an LSP server can, so you use them together, they don't really compete with each other
Reports vary massively on how useful Copilot is, some people say it makes them 3x as productive whereas others say it just gets in the way, I think 30% is a conservative estimate if you are working with the kind of code that Copilot is good for (front end JS/TS and backend python).