If something takes 10x the effort for 0x the return most will not do it.

I agree there is definitely more work required to get something working with IPv6 (though not 10x). However to say that doing this is "0 x the return". You're ignoring a solid third to half of the broad internet, which is not nothing. Plus if you're trying to sell to me then I'm definitely not going to adopt your product if you've made no effort on IPv6.

if the Internet actually managed to move to v6 the end of NAT and CGNAT would be a huge win.

Also, look at the price of every v4 address you have to rent, and compare it to v6 and tell me there's no return.

I've practically built an entire career out of finding ways for customers to use fewer v4 addresses and the demand is there because v4 addresses are expensive as shit due to their scarcity.

It takes as much or less effort than IPv4. And sorry if you set up networks and don’t know how to do that with IPv6, you shouldn’t be doing what you are doing. If it takes you 10x as much effort to set up something that is actively simpler, you need an education or a career change.