You need to understand any language, and any quirk of that language, in order to effectively write in it.

That seems to imply they all have the same amount of quirks, which I think most people here would agree is untrue

Something like Haskell has far, far fewer quirks than x86 assembly code. It really only has quirks to do with interactivity; everything else is very predictable and visible in the code. Meanwhile, assembly code is but a maximally useful set of quirks in a specific electronic circuit.

Ditto if you look at older languages. FORTRAN is unpleasantly quirky, which is why it's almost obsolete.

If that wasn’t the case, we would have one objectively “perfect” programming language to use in all situations, on all machines, for every use case.

I mean, I hold out hope that that will eventually happen, at least for the vast majority of use cases and machines. Obviously we're not there yet.

There have been languages that basically dominate their own niche. C/C++ was almost the only game in town for performance coding until someone discovered a way to compile mid-level code while also guaranteeing memory safety. Memory errors were a terrible quirk, so now Rust might steal its crown.