The biggest thing missing from helix right now imo is plugin support, so a lot of plugins that I really like wouldn’t be available. I use fugitive a lot for working with git for example.

Another one is the quickfix list in combination with ex commands. One thing you can do for example is setup :make to run your compiler and then when you get compilation errors they’ll show up in your quickfix list. You can then use :Cfilter to focus on one type of error and then :cdo to for example do a find and replace on the remaining lines.

In general, if I don’t have an lsp available for whatever reason (I work in cmake a fair amount at my $DAYJOB for example) I would much rather use vim, in particular because of the stuff that you can do with ex commands that I mentioned above (also works great with grep) but also because of the ctags support.

Helix can do a lot of nice things out of the box for a lot of cases of software editing, but it’s not nearly as broad or as customizable of a tool as vim

Vim still has a lot of advantages over helix. Being modern doesn’t automatically make a tool better