It is a massive difference. I do not like magic compilers. The JSX transform is trivial and not even necessary, just create a factory function and React.createElement becomes arguably more readable, just not HTML like.

Is it a massive difference, or is it a small difference? At the end of the day 99% of React projects have a transpilation step and utilize some form of “magic compiler” somewhere along the line.

The simplicity of JSX is overvalued. It just means more code, and typically uglier code, to achieve the same behaviour as Vue. Which is basically the theme of React when you compare the two libraries.