Most decent bikes today won't need to have their BB shells faced. Many decent bikes BITD didn't need it either. If you bought a vintage bike from the past that was actually one of the cheap bikes made in the past but now for some reason are highly regarded, you might need to face the BB if it hasn't already been faced. Like back then, if you are buying a cheap BSO today, it might need it's BB shell faced.

The differences in type of bearings used in the BB today also make them more forgiving of small deviations that some in the past wanted to be persnickety about.