That's what I mean by niche layered on niche- the editor itself is a niche project that leverages another niche project (tree-sitter) to do indentation, and when contributions on either aren't up to par it kind of falls apart.
I have used the editor a decent amount and it's quite nice when it works. I don't even mind the lack of plugin extensibility because there's not really anything I needed that wasn't built in.