There is never a reason to not back in, and the end result is always a better parking job and an easier exit.

With the exception of diagonally placed parking spots next to a one-way lane, like the 30-60 degree ones here: https://www.dimensions.com/collection/parking-lot-layouts.

If the lane is wide enough you might be able to back up into a 60 degree one, but I'd hardly qualify it as a better parking job or easier exit.

With regular parking lots I fully agree that backing up is usually far superior.