> Do you mean generally, or by default
We don't have to change the existing behavior if there are concerns about backwards compatibility. But it is a common situation where you want to define bindings in a minor mode, but you don't want them to override minibuffer bindings. This often comes up in completion packages such as
https://github.com/raxod502/selectrum, and there is no existing solution in Emacs---all the options are more or less hacks. If there were a way to make this happen, then it would be a great improvement, even if it weren't the default.
I can indeed think of situations where you want to override a binding globally, so it seems like it would be best if there were ways to declare this behavior on a per-mode basis.