I think this is a lack of imagination. The fact that (CG-)NAT is in the way could be precluding the development of software that could take advantage of incoming/P2P connections.
It's a form of (negative/inverse) survivorship bias: kind of like zoning for only single-family homes and yet saying "no one wants mid-rise towers/apartments as evidenced by the fact no one building them". The current rules/structure preclude any other options.
When we went from dial-up speeds to DSL/cable to fibre we were able to have all sorts new applications due to higher bandwidth. Are there classes of applications that we don't / can't have because of NAT? We're stuck with things that often need a central server (TURN/ICE/STUN) and I'd like people to have the ability to explore a more distributed/decentralized Internet.