Those newbie refactorers took a 300k line codebase, removed 130k lines of cruft, got it working on a modern toolchain, created an actual OSS dev community without a bus factor of 1, and added two major new features (async and embedded terminal) of which vim has only gotten around to adding 1, while improving performance and laying the groundwork for another major new feature (embeddable) that vim will take years to catch up to.
And all of that while maintaining such good backwards compatibility that almost all vim plugins work unmodified. Plugin authors only need to lift a finger to take advantage of new capabilities like async.
I didn't switch just for the sake of moving on. I switched because by any appreciable aspect, neovim and the developers behind it are simply better than vim.