Yeah 9 is just powerful enough to reliably achieve good expansion and penetration on human sized target.
A good 9mm will expand to somewhere between .65-.75 and good .45 .75-1". Is that extra 1/4" diameter gonna help? Maybe it will, maybe it wont, depends where you hit.
Also heavier and slower pistol round retain the goldilocks expansion velocity for longer than the lighter ones, they start slow, but lose less over time due to drag since drag is lower at lower speeds. That is if you can actually hit anything at the distances where this matters.
.45 is one of the quietest major pistol rounds being relatively low pressure, are you ever gonna be in a situation where you might need to shoot unsupressed pistol with no earpro indoors? Consider that.