Why not? We go through shortages all the time. If I can only get bullets of a certain weight or certain powders I want any handgun I own to be able to shoot within reason with what I have available to me. Adjustable sights makes this easier. You do you though manDefinitely not, the 45 Colt is probably the worst in the world about POI's changing when you switch to lighter bullets.
The question is, why dick around with a bunch of different bullet weights and twiddle with your sights?