I think a lot of Babel is for people who haven't kept up with caniuse statistics and don't realize that the "low water mark", the "well supported baseline", has moved to something very close to ES2021 or more recent. To be fair, Babel is explicitly targeting some of those developers that prefer ignorance and don't want the mental overhead of actually knowing what browsers support and like having "just use the presets!" attitude. I think some of them would be surprised how extremely little most of the standard presets do in 2023 because there are increasingly few things to downlevel.
I have especially long been of the strong opinion that you never need Babel and Typescript. There's nothing that Typescript supports that it can't downlevel itself and tslib is a much tinier runtime dependency (if you choose to have Typescript import it rather than embed it in place) than any of Babel's runtimes (including their core-js dependencies) even when a bundler is tree shaking most of it out today (because caniuse statistics say yagni).
It still amuses that for instance the create-react-app "best practice" in its Typescript template is to use Babel for type stripping and downleveling and delegate the Typescript compiler only to type checking. No wonder people find modern pipelines bloated. To be fair, I get why CRA likes the conceptual simplicity that both of their core templates use the same Babel presets and pipelines given to them Typescript is still the opt-in "extra".
(Also, I have no problem with esbuild doing my Typescript type stripping and running tsc as a separate pass in esbuild pipelines, but esbuild isn't pretending to do a lot of unnecessary downleveling in 2023 and adds no further runtime beyond the parts of tslib it bundles for you. It's mostly just Babel's extreme complexity that I find redundant and unnecessary and its labyrinth of presets that don't actually do much in 2023 but give the impression that they do.)
Es6 arrow functions are a good example of this. They have been around for a long time and work in most browsers, but people learned they need babel to transpile them out for internet Explorer. People dropped ie support but the knowledge "we need babel for browser compatibility " remained an entrenched fact.
Yeah, it's relevant to remember that arrow functions were defined in ES2015 (eight years ago) and like I said most browsers people are using are caught up through at least ES2021. The nice thing about the ES2015 year-based nomenclature (as opposed to the people still calling it "ES6") is that you can do a quick reasonable first approximation of caniuse statistics off hand with "is that standard at least two years old?" Arrow functions are old.
