I tell people that they can get approved for more than they should be comfortable borrowing.
I have seen approvals as high as 60%+, but with compensating factors. Many people have some income that underwriters will not count. Many self employed have more income or those with bonus/commission/overtime cannot always be used.
In a society where the govt encourages spending if it took 20% down and 30% debt ratios to qualify for a mortgage, you would see home prices much, much lower, but that just wouldn’t be good for an artificial, phony economy. Don’t expect to see it anytime soon.