Is it possible to combine ui libraries?

Question

React

Good evening, there is an application, the client part is ready, without using any UI libraries, but the admin part, I decided to take material ui.

So the question is, how do they usually do it?
I think it's logical to divide this into 2 separate applications - client and admin, but the "familiar frontender" said that it can be combined.

Is it bad form to combine ui libraries? (I think so, but a friend confused me)

Answer 1

can all mushrooms be eaten?
all but some - once

the tone is not bad, you can do anything: the master-master pays, even insert jQuery into the admin panel (and why not - there are obviously back-end integrations, in Jang and Laravel it’s so accurate - don’t drink water from the face, in the admin panel the main thing is functionality and not beauty)
and do not mix for this reason - to make it easier to support progers with limited competencies