As another neovim/vim expat using VSCode these days (because I got tired of fixing configuration), this is also my number one complaint. I want to be able to view any file in any split. Honestly, I wish my whole window manager worked this way (stacking WMs get close). And my browser - why can't I display any "tab" in any window with a couple of key strokes? It drives me batty how inflexible the split/buffer/pane/window model is outside of vim and emacs land. I don't want tab groups; I don't want independent windows; I don't want VSCode editor groups that are pita to close. For the love pixels, I want to make the content I care about appear in the window I have in front of me, where those windows are arranged to consume my monitor's space without overlap. /soapbox-dismount.

Not that guy but how about viewing two parts of the same file side by side, organizing them vertically or horizontally as needed, opening like a hundred files and cycling through them in a sane fashion, probably dealing with macros. Tabs get very annoying if you have too many of them, and buffers are a good solution to that problem.