I think you're right up to a point. For my office router I'm indeed using my own gateway in front of their modem which is acting as a bridge. But for my home network, it's the default gateway that came with my fiber service ~8 years ago that a ton of people still have.
My sense is this transition is going to take another 10+ years to get done. The big web properties where most people spend most of their time have the IPs to maintain IPv4 indefinitely, which will slow it way down. It's the smaller apps who are going to want to deploy IPv6-only who will generate consumer complaints: "I don't understand, why does Google work but this app doesn't? Why does it work from my phone when I'm out and about, or from work, but not from home?" The consumer won't exactly know who to direct these complaints to, the cause is non-obvious to most "tech support" people, and the fix is either too complex for consumers to implement or involves getting new equipment.
My sense is this transition is going to take another 10+ years to get done. The big web properties where most people spend most of their time have the IPs to maintain IPv4 indefinitely, which will slow it way down. It's the smaller apps who are going to want to deploy IPv6-only who will generate consumer complaints: "I don't understand, why does Google work but this app doesn't? Why does it work from my phone when I'm out and about, or from work, but not from home?" The consumer won't exactly know who to direct these complaints to, the cause is non-obvious to most "tech support" people, and the fix is either too complex for consumers to implement or involves getting new equipment.