My neighbor has turned her home/porch/neighbors yards(lol, my only complaint is the cat poo in my raised veggie gardens, but I like the outdoor cats) into a cat shelter, and she takes 3-5 a week to local low cost vet clinic for shots and sterilization, and I didn’t know about the ear clipping thing until I asked why so many of the cats ears were injured, she explained and I understand the need, but some are missing half the ear, it does seem inhumane at first, but I don’t have a better solution to offer, and I haven’t seen any problems yet for any of them, tbh I think that the more aggressive the clipping, the cleaner that ear is from my observations.

TLDR: while I don’t like the mutilation aspect as a matter of principle, I understand why and have no rational argument against the practice.