ガブリエル

This has been a thing since Linux kernel version 5.0.

How come it doesn’t work? Which compositor are you using?

I’m currently using Gentoo. That means I should also grow my own food…

To complement your answer, usually people want tree-sitter not only for smart selections, but because of syntax highlighting.

Kakoune has the best of both worlds: https://github.com/kak-lsp/kak-lsp supports semantic highlights from LSP servers, but we also have projects like https://github.com/phaazon/kak-tree-sitter in case you want highlighting from tree-sitter.