It is not worse or better -- it is just different. It is different in ways that may or may not matter to you.
Naturally with both Vim (classic?) and Neovim there are people who invest energy championing one or the other. That is just human nature.
You might think that "Neo" means new (and it does). To cut to the chase, if you are a long time vim/vi user and you don't use plugins or intend to hack on vim, either one will do you just fine.
At the basic level (for a beginner who has mastered what is in the vimtutor), there should be no difference at all. You can run vim on even days, and nvim on odd days and not notice any difference.
For someone who just uses vim, it doesn't matter -- or it had better not. If you want to start using plugins, or in particular writing plugins, then it matters a lot as with NeoVim you can use the Lua language, and with Vim you will use Vimscript. And of course this means that there can be issues with plugins that work for one and not the other.
Clearly a plugin written in Lua won't run in Vim classic. Neovim supports original Vimscript, but Vim 8 added some features to Vimscript that Neovim doesn't support, and more of that took place with Vim 9. So a Vimscript plugin that uses these new features won't work with Neovim.
At this point, I do not use plugins and I certainly don't write them. Never say never -- this is true now at this stage of my Vim journey. Be advised that as of Vim 9 (I currently run 9.2) Vimscript is greatly improved, runs faster, and even has some new features. Many of these improvements were provoked by the Neovim project.
On my linux system (Fedora 43), typing "nvim" gets me NeoVim, currently v0.11.6 (as of May, 2026). At least it does after I do "dnf install neovim".
As already mentioned, the most obvious difference is that NeoVim incorporates the Lua language in lieu of Vimscript in normal vim. In general, Neovim is more friendly to people who want to hack and augment the editor.
This is important if you want to customize the editor in some way. It also means that there is more activity and energy in the NeoVim world. Even if you aren't writing plugins, other people are and you may find interesting things available for NeoVim that won't be available for Vim.
I am only beginning to investigate NeoVim, so these comments are all somwhat preliminary.
Tom's vim pages / tom@mmto.org