I don’t use Helix myself, but I’ve tried it before.

I believe I’ve heard many users requesting a plug-in system (there were some plans for Scheme?), and that the devs themselves considered many features as more appropriate for plugins than first-party support (code folding and non-LSP snippets, if I recall correctly?). I don’t know how Helix developed the last couple of years, but if features like that didn’t materialize yet, that sounds like sufficient impetus for a fork to me.