IPv6 vs. 4 is like Python 3 vs. 2, just worse.

There are genuine improvements in IPv6 aside from the abundance of addresses. The two that immediately come to my mind are:

1. SLAAC means routers no longer need to keep a record of each client on the network. With DHCP, the router had to maintain a table of which addresses had been assigned and getting an address involved 2-way communication. With SLAAC the router just periodically broadcasts the prefix to the network and any device that wants an address can just listen to that broadcast and assign themselves an address within that prefix without having to inform the router and without the router needing to maintain a table of assigned addresses. (2-way communication is still possible since devices can solicit a broadcast but it is not necessary)

2. With IPv6, middleboxes are no longer allowed to fragment packets. The only device that can fragment a packet is the original sender. If any segment along the path has a lower MTU than the size of the packet, the original sender is notified and then they can fragment the packet.

And IPv6 vs v4 discussions are just like Python 3 vs. 2 discussions: Often much more annoying than just getting it over with and switching.

Python 3.7 or Python 3.8 ? /s