IMHO, the worst thing about dual-stack is that you have to do it at all. There are translation mechanisms but that doesn’t help when you have local devices (maybe IoT?) that don’t support IPv6.
I think that's why this new IPv6-Mostly stuff is so exciting. You can dual stack a network segment if some of those v4-only devices exist there, but IPv6-Mostly will make sure that the other devices stay on v6 (translated or native).