Not only from just existing, but between going to the gym a few days a week and doing regular cardio on other days, I just can’t imagine the absolute rank stink from not showering regularly. Once I thought I didn’t work up enough of a sweat weightlifting in the gym so went to bed when I got home, and the bed smelled like absolute trash the next day and neither me nor my partner could sleep there again without washing everything.

Maybe it’s just my neuroses or mental illness, but I can’t imagine smelling so badly and not showering even if I didn’t socialize with others, and can’t imagine I’d have many people to continue to socialize with (in USA so this is probably different in the OP’s country) if I smelled so bad when I went out.