Online gaming: No "strict NAT" program. No conflicts with having multiple consoles at one locations. No port forwarding needed.

VPNs: Business IT usually uses some weird IP range like 172.xxx.xxx.xxx so avoid conflicting with the popular 192.168.1.xxx or 10.xx.yy.zz. When two companies merge there is now an IP range overlap and a renumbering has to be done.

P2P file transfers: No port forwarding needed.

Self-hosted servers: No port forwarding needed.

Video chat/VoIP: One reason video chat still suffers from bad quality is that video is proxied through cloud servers to deal with NAT. With more IPv6 video chat services can use more direct connectivity lowering costs and improving quality.

Avoiding CGNAT. If anyone on the same CGNAT group in your ISP got banned you will also be banned. Many Internet services don't have IPv6 and they often cite IPv4 based reputation as the reason why they won't deploy IPv6.