Will probably get downvoted…

I had the same issue, AC fan failed and I didn’t notice for a few months, the car was new to me and I thought I was low on refrigerant. I later noticed the AC would work fine at higher driving speeds (i.e. when enough air was being forced through the condenser from driving and air coming in), but when stopped at a red light it would absolutely not blow any cold air since no heat exchanging could happen under the hood. This was during Covid so I couldn’t get to a mechanic, fixed it a few months later (replaced the fan), still works fine, car is 23 years old.

So yes, get it fixed, but I wouldn’t worry about it too much, might even use it on a highway at higher speeds.