Gpt-4 can do math just fine.
Ask it to add any arbitrary set of random numbers it'd never have seen in its training set and it will do it.
GPT-4 is good enough at math that khan academy feel comfortable hooking it up as a tutor.
Have you actually used GPT-4 for any of the things you say it's bad at ?
Man the confident nonsense people spout on the internet is something to behold.