90 is kinda the middle of the wide-angle pack and relatively versatile. There was a time when photo
schools, given the general poverty of students in general, recommended that the first lenses to be
purchased for 4x5 would be a 210 (good image circle and tight enough for head and shoulders portraiture) and a 90 (interiors, studio setups). This simple combination allowed most bases to be covered, at least at a teaching level. Only relatively recently have lenses shorter than 90 been available
with significant wiggle room for movements. That is always a primary concern.