No one is forcing you, but the React docs say "If you want to build a new app or a new website fully with React, we recommend picking one of the React-powered frameworks popular in the community. Frameworks provide features that most apps and sites eventually need, including routing, data fetching, and generating HTML."

So, it going to be difficult to choose pure React with that kind of statement.

Even using React v5 without a state library for a large app was bonkers back then, regardless of what the library maintainers said.

At some point you will have some state that transcends the UI and trying to shove it into React UI component does not make sense.

How is it difficult? Tons of companies have profitable UIs that aren't using a meta framework. Just because the React team says "we recommend you do X" doesn't mean you have to do X. If they said, "you must do X" then yea, you should do X