GCP IoT Core Shutting Down - PubSub as replacement?

[fisehara]

The IoT Core is a device registry and some proprietary MQTT server with single device authentication.
Inside of GCP the IoT core sends all inbound data (from device to IoT Core) to a PubSub topic.
Maybe a replacement for the IoT Core is utilising the PubSub for inbound and outbound messaging.
Configuring and distributing PubSub secrets for a single device could be managed with balena environment variables.

Link to PubSub here:
https://cloud.google.com/pubsub