I think the Matter standard is going to cause IPv6 adoption to increase significantly in the coming years. People will demand it, without even knowing what Matter or IPv6 are. They just want to be able to turn their lights off from their phone without any extra hardware or software.

Matter is only local networking. Essentially everyone has IPv6 on their local network.

That said, I disagree with the parent statement that v6 isn't going to happen. It's already happening at a steady rate. From the Google stats it's steadily rolling out. Some countries are reaching 100% v6 deployment. I wouldn't be surprised if we eventually see some countries with high v6 deployments see services which are v6 only.

They've had years to demand it, I don't see why it would suddenly change. Most users who buy "smart" appliances are not power users, don't set everything up themselves and just rely on manufacturer's servers anyway and don't need a direct connection - and are okay with it.