Opposite experience for me, we went from 1 to 3 cats by adding the new cat every 6ish years.

Didn’t really do anything special, just brought the new cat home and that’s it. Maybe has to do with all of them being from the same breed (Oriental shorthair) and the specifics of the breed itself

True, it’s a lot of paperwork and not the most efficient, but I can trust that it will work

Even in tech, there are things that probably haven’t changed in the past 25 years