The only one I can think of, literally the only one, is grouped icons.
And even that's only because browsers ended up in a weird "windows but tabs but actually tabs are windows" state.
So yeah, I'd miss the UX of dragging tabs into their own separate windows.
But even that is something that still feels janky in most apps ( windows terminal somehow makes this feel bad, even VS code took a long time to make it feel okay ), and I wouldn't really miss it that much if there were no tabs at all and every tab was forced into a separate window at all times with it's own task bar entry.