Agreed! But as IPv4 with NAT has an implicit "deny all inbound" firewall rule, in the IPv6 world many routers will default to "deny all inbound" to any "inside" IPv6 addresses. So game servers may benefit from an outside coordination server (so bidirectional traffic can flow) but unsolicited inbound traffic to web servers would still require some configuration at the firewall.
Absolutely in the P2P case it is fantastic. IPv6 effectively guarantees direct connection for WebRTC audio/video, VPNs like Tailscale, etc. However there is still some necessity for video services that can provide a Selective Forwarding Unit, for instance once you get 5+ people in a video chat, you want a server in the middle to mediate and rescale video to manage the experience for all participants. But for sure it is better for everyone for 1-on-1 chats to be able to establish the connection without an intermediary, and that underscores what the Internet is all about.
Having globally routable addresses is a pretty big upside. For nerdy types, it means you can run web/game servers at home (i.e. without needing a credit card), which is a way for kids to develop their technical interests.
For the rest of society, getting rid of NAT is a requirement to allow seamless p2p apps to work without needing to use giant corporations in the surveillance business as an intermediary. Instead of being jerked around with Google moving people onto their 15th video chat app with potato quality, we have the necessary foundation to be able to directly connect with your counterpart. This could be completely seamless with e.g. a DHT to locate your contact's devices (or gossip if you can reach at least one that you already knew about, to maximize privacy) and uPnP or hole punching to their address to open your router's firewall.
NAT forces centralization for our foundational ability to communicate, which robs everyone of their autonomy in ways that are so pervasive it's increasingly hard to imagine another world. But that other world is still possible.