Of course it is, but saying it's "a ton of complexity" to use JSX, while not saying the same for transpiling current and future ECMA-262 syntax into what browsers support right now is disingenuous.
No it's not, transpiling future ECMA-262 is not within the scope of this discussion. We are compared browser-native language features JS (non transpiled), HTML, CSS, to non-native features, namely JSX.