These sort of basic features seem like the hardest thing for AI companies. OpenAI only recently added a way to search all your chats. Gemini still doesn't have that.
Also, you may be underestimating how buggy Swift and the rest of Apple's stack are. It's hard to get those bugs resolved unless you happen to work at Apple. Thus, a lot of time is spent working around bugs up the stack. So I don't find it surprising that a company moving fast like OpenAI ships _some_ bugs. The mac app just came out this month? Give it time.
It's odd that things like that are what they're missing.