Undermining your point is that math papers don’t get published in nature and most math papers just go up on arxiv not journals. Are you sure you’re familiar with how academic mathematics works?
I am pretty sure that journal publication is the norm. I do know mathematics although I am not one myself. The mathematicans I know want/need journal publications as unpublished research isn't counted in their research output. I know Arxiv is typically used for preprints while awaiting review but publication is always the aim.
Don't take it from me though. zbMath did a study finding 60-70 percent of arxiv papers on math end up in peer reviewed journals. https://ems.press/content/serial-article-files/47210.
If they’re untenured sure. Tenured mathematicians care a significantly deal less.
> Don't take it from me though. zbMath did a study finding 60-70 percent of arxiv papers on math end up in peer reviewed journals.
Elite journal capacity didn’t expand. There’s just a bunch of mid-tier journals helping to absorb the increased publishing to help these ~indentured~ untenured professors.
You are right that most work gets published in mid tier journals. These are still peer reviewed. The difference is that they have a lower bar for impact. The bar for correctness is still very very high however.