We used Pub/Sub very extensively (50B messages a day) but moved to Pulsar [0]. It performs equally well and has some nice features. And also no vendor lock-in.
[0] https://kesque.com/billions-of-events-a-day-without-breaking...
[0] https://kesque.com/billions-of-events-a-day-without-breaking...
They have an open ticket [0] to dilute zookeeper's dependance, but as far as I know it's still pending.
Stances are not strategies, when we use another's API we form a bond but the the other is free to break it so we are automatically at a weaker position. We have acquiesced. But if we choose a strategically worse choice, we have not only acquiesced, but done self-harm.
Otherwise, eg, FOSS is "nothing good".