Earlier quoted context omitted.
This is untrue. Tons of development is done by others.
I mean: https://github.com/vim/vim/graphs/contributors https://github.com/neovim/neovim/graphs/contributors technically yes (by others too), but relatively, it's basically a one-man project
Here are contributor lists I've gathered a few years ago from `:help versionX.txt`: https://gist.github.com/romainl/7b17317cc26a30116e51a3759022...
That's 600+ non-Bram contributors up to the fork that the Neovim team made disappear from their project when they removed the relevant files.