I was having the same thought when purchasing my new place.
Previously my family stayed at a condo with separate car park building, there are times when you forgot something in your car, you will need to take the lift all the way down, cross the other building and walk up the stairs to your car floor (Didn't have lift at that time for the car park).
Imagine the hassle if you need to carry heavy loads like groceries.

I found that annoying so I prefer car park below the residential units.