Just because "Every React codebase I've ever worked in has used JSX" doesn't mean "you still need to transpile JSX in most scenarios". Of course, if you're serious about using React, doing the transpilation before pushing your code to the CDN probably makes the most sense, rather than doing the transpilation client-side or using vanilla JS. But just because it's common, doesn't mean you need to follow that way of doing things.

You just admitted that "it's common". That's another way of saying "in most scenarios". I don't know why you're splitting hairs like this.