In our case, we back out of the garage about 50 feet where we can turn around and leave the driveway front first. If we were to back in, we'd have to make the turn around the same 50 feet from the garage door and back up the 50 feet into the garage bay. With an 8 foot wide door, there's about 6 inches or so of clearance on the mirrors on either side. I've been driving for more than 50 years and consider myself a pretty accomplished driver, but backing the 50 feet twice a day for 3 years, I'm 90% sure I'd be needing a new mirror by now - For the wife . . . . we'd have needed a new mirror the first month
Pulling in nose first, the car is already aligned very straight in the garage stall and backing out is a simple matter - You just don't turn the steering wheel at all . . . . it went in straight and it comes back out straight. You could back it out at 25 miles an hour and never clip a mirror. Once you clear the door, the driveway is 20 feet wide. Backing onto a 20 foot wide paved surface is much, much easier than backing a 7 foot wide car into an 8 foot wide door
As I said previously, "Backing into a confined space so you don't have to back out into an unconfined space will never make a lick of sense to me" - It's cheaper too . . . . no need to buy the occasional mirror
The other really good feature about backing out vs backing in - You can walk around the back of the car before you get in to leave the space to assure there's nothing behind you before you begin the backing operation.
When I was in the USAF, we always had to use a 'backing spotter' (the front seat passenger who would get out and stand behind where the driver could see them in the mirror.) No passengers? We had to use a back-up cone. Stop the truck, place the cone where you wanted the drivers side rear bumper to be and then get back in and back up to the cone. Something like 75% of all our accidents happened while backing. It got so bad that ANY backing accident of any kind was an automatic Article 15 or worse - Not good if you were a career military person hoping to retire after 20 years. Back-in parking was a definite no-no