React does not force JSX use. JSX just compiles down to React.createElement.
I feel React.createElement is so unergonomic it's not really an option to use directly. A lot of React supporters mention it when people criticise JSX, but I don't think it's a pragmatic alternative.
I know people who use React without JSX and it reads fine, as long as you assign React.createElement to a shorter alias. I like that you don't have the visual noise of closing elements. I think it's mostly a matter of taste (and how much you care about your HTML-generating code resembling HTML).
React forces JSX use, so a lot of times the battle between Vue vs React seems to be Vue Templates vs JSX which never makes sense to me.