If there is anyone trying to find a way to migrate from Google, Qubitro offers you a warm welcome.

The offer for six months of free credits as well as free technical support and more is here: https://blog.qubitro.com/migrate-from-iot-core-to-qubitro/

It is unfortunately the least garbage of most of the cloud providers, but until it supports MQTTv5 out of the box then it is useless for most modern MQTT deployments