Last week I thought I'd finally get round to converting my existing Neovim init.vim config [which had itself been inherited and developed from my earlier Vim .vimrc one] to Lua [not a language I'd ever used before. But the syntax looked fairly straightforward].
What a waste of time! The easy stuff [enabling/disabling various options] was easy. But then it's easy in Vimscript too. The difficult stuff [defining autocmds, managing my plugins] was either completely ignored in every single "convert your init.vim to to init.lua" tutorial I read... or required wrapping the existing Vimscript block in
vim.cmd[[ ... ]]
I spent the best part of a day wrestling with converting to init.lua, left it overnight and then, in the morning thought Why the fuck am I wasting time trying to beat this into shape, when my existing vim.init is already set up exactly how I want it?" and I reverted back to good ol' crusty ol' unfashionable Vimscript.
YMMV if you're actively developing plugins and want to use a more widely utilised language to write them in. But for configuring Neovim itself, Lua is more hassle than it's worth.
That's the reason a DSL is usually better in these cases; I've used lua for scripting game engines before but I don't think it's a good choice for a text editor, especially an established one like vim.
If you use anything more complicated than toggling settings and autocmd's in your vimrc, I suggest you take a look at `vim9script`, it really is an enormous improvement.