If I could wave a magic wand, I would implement this like some kind of token replenishment or quota system like every IP address gets to access old dot like a very low number and if you log in with the same IP address you get more quota or replenished a little faster if you also come in with no auth like from a private window. Of course, in an ideal world we wouldn't have to do anything like this but yes, regional is likely as well.

I know I worked with some programmers in India and apparently some ISP will do some kind of trickery so like a lot of customers share the same ipv4 address. So what I said above might not actually make sense in the real world.

Is that trickery NAT, network address translation? It is a pretty widespread technique I think, we’d have run out of ipv4 addresses a while ago without it.