With nvim, there has been quite the resurgence of Vim. Good software tends to be resilient. I believe both emacs and vim will see many, many more years.
MANPAGER=nvim --clean -c "colo sorbet" +Man!
My current config is pretty stable, and not that large. But if it were causing issues, I'd seriously consider only doing LSP setup, which is not that onerous with the latest APIs (it was already fairly easy with `vim.lsp.start`, but `vim.lsp.config` and `vim.lsp.enable` make it easier still: https://neovim.io/doc/user/lsp.html).
Apart from that, I don’t really know what an application would be to Emacs as nvim is to Vim. It’s more like nvim is to Vim what Emacs is to nano, except Emacs came first.
A multithreaded version of emacs would also be an interesting addition; I read some arguments against moving emacs to a multithreaded model, but I don't really remember them.
Everyone including the maintainers would like this to happen. The arguments against it are technical hurdles. Emacs is a large ball of global state and the lisp evaluator hooks into everything, including the display engine, so it's not clear to anyone how to disentangle things to the point where the interpreter lock can be released.