Why is it that doctors appointments are something that you need to set aside time to make, personally? Why can't somebody else do that for OP? I don't personal

Why is it that doctors appointments are something that you need to set aside time to make, personally? Why can't somebody else do that for OP? I don't personally need an assistant, even though I work at the same company as my CEO (who has a personal assistant as well). Him having one doesn't mean everybody needs one.