IMO it is not that surprising that neovim has had some success, in the same way that it isn't very surprising that SwayWM has had some success. They both have the benefit of, in many cases, being completely compatible with the tool they want to replace. Being almost completely compatible with the old tool, while integrating a popular new technology (LSP or wayland) seems to be the only way to win over users who already have a strong connection to their tools of choice.

My vimrc already has a bunch of configuration in it, I'll give Helix a try when it is able to parse that (so, probably never, I guess).