Copywriting in languages other than english?

This question was inspired by another thread here in which a new writer (who I presume speaks spanish as their native language) was asking for critique of their english grammar.

Why are so many writers trying to build a writing career in english, though it's not their native language?

Aren't there markets for copywriting in their native languages? Don't people read in their languages? Don't people buy stuff in their home countries?

Don't get me wrong -- I'm not criticizing... If they can make english copywriting work for them -- congrats -- more power to them.

I'm just curious why they aren't participating in (or maybe pioneering) copywriting in their native languages.

Is it a matter of first-world companies paying more? ... Or maybe products aren't marketed using direct-response copy in poorer countries?

...Even without searching google, I'm sure there's such a thing as copywriting in other languages... There must be copywriters who write in spanish, french, chinese... Why not bengali or hindi or urdu?

Here's an example of a writer aiming to exploit the english-language business market by helping people crack japanese markets using his japanese copywriting skills: Toshino Momoki Japanese copywriting and creative services

Why aren't other english-as-a-second-language writers using that business model? ... Or even marketing their copywriting skills in their home countries?

Again, I'm just curious about the subject. Not trying to discourage anyone from pursuing markets for english-language writing...