I started zwift when it was beta and only Jarvis. Yes it was a god send and has led to better training and safer riding in the winter. Everything you say is true.
The issue is, it’s not Zwift per se, but indoor cycling that is the game changer. Zwift were first mover, but no longer are the only option and in my opinion certainly not value for money.
You may not be aware but 2 weeks before the prices increase Zwift also cancelled the ability for kids to have free accounts rather quietly. So that has been taken away for parents.
Now the option for kids to ride with parents would have to be another platform.
My wife and I both Zwift together on our own sets ups at the same time. Last night we rode together on IndieVelo and will from now on. That saves us £36pm which isn’t small change to us.