Meta/Facebook preinstalls an app called Meta Services (previously Facebook services) on a very large percentage of android devices (I’ve never used one without it) and while they claim it helps updates and synchronisation between different meta apps, it is very suspicious. Why preinstall it on devices of people who will potentialy never use a single meta app?
Go to your app list/app management and show system apps and find anything with the words “meta” or “Facebook” then turn off network access for those apps (if you can) and disable them. (eg. Meta app manager, Meta app installer).
https://www.askwoody.com/forums/topic/meta-services-an-android-app-or-not/
https://fixyourandroid.com/about/facebook-app-manager/
https://www.reddit.com/r/GalaxyS20FE/comments/ttmx4t/meta_services/
Edit: Looking around I have found several people complaining that this app is using their ram for 10 hours a day even though they don’t use anything Meta. That’s even more suspicious.
All the phones I’ve had come with bloatware like this, I currently have a Xiaomi phone and MIUI itself is bloatware, the ROM is full of ads. Thankfully there is an “adb” software for Xiaomi phones that allows you to disable or remove this pre-installed malware.
Of the cheap Samsung, LG and huawei phones that I’ve had they also come with random bs pre-installed that can’t be uninstalled without the help of third party software.