Now, I can simply restart my router (or cycle airplane mode on mobile) and get a new IPv4 that probably was used by bazillion people before me, or even along with me, and get a new account. So Google has to be very careful here, with IP-linked bans in order to not just ban the whole load of unconnected people just because they used the same IPv4 as me.
With IPv6, they could just ban my entire family and any guests that might have connected to my WiFi, forever.
I like the limitations of IPv4, thank you.