Through non-google message brokers.

The problem is that this requires a long running background connection.

And guess what Google tried to kill for battery saving purpose since a long time (long running mostly sleeping background processes). But then on Google in difference to Apple it's still possible (but less reliable) with the right setup and fully possible with a "proper" de-googled phone.

So depending on your setup you might either:

- not get notifications

- get them unreliable

- only get them if the app is open

- get them just fine

Also this might change from app to app, there clearly will be apps which will not have any 3rd party notification broker fallback, but given how Google doesn't have 100% delivicery guarantees they still should have (potential delayed) message syncing when the app is open.

I think I don't.

Sometimes I get notifications, sometimes it may take hours for me to get the notification.

I rarely use instant messaging for important things, and when I do, I make sure to check my phone often so I don't miss the messages.

Is this stupid? Maybe, but I'm not going to install Google's closed source crap on a device that I carry almost everywhere. If that means I become a social pariah, then so be it.

Both Signal and WhatsApp work fine. It requires workarounds from the app developers, but it's not impossible to implement.