I'm tired of having to correct people, but I will do it anyway.

Disagree, it serves to illustrate the same kind of monopoly google has one push notifications.

This is wrong. If you look up the definition for monopoly, you will realize it is false. At worst, it's a duopoly. If we exclude Huaweii Push, etc.

UnifiedPush is not a push service, it is a distributor. It is a proxy for push services, it does not send out its own notifications.

That is also wrong. Idk how you got the idea of it being a "proxy".

"UnifiedPush is a decentralized push notification system that lets you choose the service you want to use. It’s designed to be privacy-friendly, flexible, and open — making it perfect if you want control over your push notifications."

https://unifiedpush.org/