When I'm using an IDE (vim-based or otherwise), I tend to have other things integrated into the editor session, for example I'm connected to a REPL or other external thing. If I pop a tab out into a new window, I don't want it to be an entirely separate editor session: I want it to keep all these extra integrated things as the parent. I still want to be able to evaluate code in the same REPL session as the parent without having to create a new session or connection.

I'm not sure how to handle something like this in a terminal editor, unless the vim plugins are aware of it (but they're not, since they weren't written for it). In a non-terminal editor like nvui, the new window could be just a view into a buffer, but still running inside the one instance of vim, allowing these plugins to keep working transparently, even though now there are multiple windows.

I don't think this is something that's easily possible with terminals without rewriting all the plugins that might need to be aware of it.