Apple reveals 'push notification spying' by foreign governments

One more reason to use F-Droid.

You need proprietary Google Play Services on your phone for notifications to work, apps need to have proprietary Google code in them for this to work, and this is a proprietary service.

You’re purely depending on Google and their proprietary services for basic things such as receiving notifications, which is pure madness. They also probably see from what apps you’re receiving notifications and when you receive them.

Good luck receiving notifications with this without FCM: Release Element Android v1.6.5 · vector-im/element-android · GitHub

There are quite some apps that only provide alternatives to FCM, Google Apps, etc in their F-Droid build.

Also, this is why FCM and APNS are an issue even if the contents are encrypted: