> One wonders, if you got rid of rats, what would take their place? No idea, might be worse.
Many cities don't have a significant rat problem and they don't seem to have anything worse as a consequence.
Friend of mine had a large hedge that ran the length of his property in a nice suburban neighborhood. Thing was a rat highway. Meaning if you think there aren't any rats in your neighborhood, you're mistaken. Probably as many rats as people. The urban forest provides.
Proper maintenance to keep rats out of housing helps with the nuisance aspect. Because rats are destructive.
One wonders, if you got rid of rats, what would take their place? No idea, might be worse. I think the current brown rats aren't actually a disease vector[1]. I've read speculation that the decline of the plague was due to brown rats displacing black rats in cities. Maybe brown rats are doing us a favor.
[1] Rat lung worm in Hawaii though is a zoonotic nuisance. Also a friend got rat lice once.