If only it were usable for really-correct parsing. In my experience error recovery is so aggressive it will accept broken ASTs without marking any node as an error. Plus, you can't really solve some ambiguities without C-based lexer hacks.

I wonder if targeting the Tree-sitter ABI directly could be a viable way to write more accurate parsers in an actual programming language while piggybacking on the ecosystem. Could tree-sitter's runtime ABI be adapted for GLL parsers instead of GLR? I haven't looked deep into it yet.