VimScript isn't all that bad. I think a lot of the hate it gets here is undeserved. It's a domain-specific language, sure, but scripting an editor is a domain-specific thing. I'm not sure if Lua would really give me a massive amount of benefit for the things I write in VimScript. Performance has never been too bad of an issue, and I'm not sure if I like programming plugins in Lua more (but I haven't tried it, so I'm hesitant to "knock it 'till I try it").

Note that in my experience the biggest performance hog tends to be syntax highlighting.

Neovim changed some defaults and such, and I need to frob with my vimrc and such to spend time on it. I'm at a point in my career where I just want to build "useful stuff", and not muck about with my vimrc. For example, the default colours don't work well with my light background.

Neovim also removed encryption, which I use. Yes, I'm familiar with all the arguments for removing it and I've engaged in discussions on this in the past (so won't repeat it here): it's "good enough security" for what I use it for, and a much better UX than the alternatives. Again, more effort.

And what do I get back for it? I can't really name a single thing that would give me an immediate benefit to be honest. To be fair, I'm a "simple" user, and don't use stuff like :term and whatnot.

Also, I'm put off by the Neovim developers' attitude sometimes, things like a Neovim dev condescendingly describing VimScript2 as "BramScript" earlier today on Lobsters is ... not great, and neither is describing various disagreements as "cop outs" (e.g. t_* settings).