Helix is great but the rigidness on Selection -> Action editing methodology is a non-starter for me. And it isn't because of qualitatively better or worse reasons, it is about mobility and universality. I need an editing scheme that is universal for maximum mobility.

I understand the creator's viewpoint (Helix was made the way he likes it), but I think it would have been better to separate out the editing logic from all the other great, overlapping features.

It would be nice to have a modern, modal text editor that allows a user to utilize an uncompromising vim mode, emacs mode, kakoune mode, or any other custom mode they'd like -- all built in natively. An editor built for everyone should not be opinionated about how one edits.

That along with things like a built in LSP, plugin management, and extensible scripting support (allowing the use of plugins would multiple ecosystems) would be really sweet.

To be fair to Mason, the answer is mostly listed in the first line of the introduction.

    mason.nvim is a Neovim plugin that allows you to easily manage external editor tooling such as LSP servers, DAP servers, linters, and formatters through a single interface.

I still use Packer, so perhaps that is not true for Lazy, but the other package managers handle Neovim plugins, mostly GitHub repositories with vim or lua codebases.

Mason installs and manages things like Language Servers, which are separate binaries running on your machine, and also starts them on demand.

Lazy.nvim uses mason to install some components.

I consider Mason integral to Lazy, some plugins require additional tools that should not be bundled like linters and formatters, and Mason is the best way to manage these.