I agree with you on UX but disagree with everything else. If you use native elisp compilation, I find its speed to rival an average editor. Completions can be slow in lsp-mode but still faster than VSCode (and emacs itself ships with eglot, a less full featured alternative to lsp-mode, but may be faster. I haven't used it enough to judge.) This is due to shelling out to LSPs and the fact that not all LSPs are particularly well built.

If you find your emacs to feel jank I highly recommend declaring "emacs bankruptcy" and starting anew with a fresh config. Defaults emacs ships with today are really good.

That said I haven't used emacs on Android yet so I don't know how well, if it all, it works. I also think the UX of emacs tends to bend toward the user's own preferences rather than good UX, and the default UX of emacs is a bit bad.