Great show! Minor point of clarification: you absolutely CAN use private repos on Docker Hub; public's not the only choice. That said (and as a complete noob to Docker/k8s/etc.), I definitely still see the value in a "deployment adjacent" container registry like ACR (which I'll be playing with immediately).
They talk only marketing bullshit about Azure Container Registry. Yet they forget to mention the private access to the repository is behind Premium SKU pricing. Otherwise the ACR runs as public registry without permission configuration.