taskbar is very much related, it is an instance of explorer exe with some parameters, that makes it show as taskbar. Try killing explorer.exe in the task manager, when no other explorer windows is running.
Yeah it probably traces back to the time when Microsoft tied internet explorer into every part of the OS just so they wouldn't be forced to remove it.
They're really bad at modernising legacy parts of the OS. Even to this day parts of the old control panel exist and it's been like a decade that they've been working on it.