For example, how do I know that the Samsung calendar app is any better than the g calendar app? Is the only way to go full open source (I’d prefer this, yes).
Also, should we stop using things like the default photo gallery? I have a feeling they steal data from that as well.
I know this is more phone related but I don’t have this issue on my pc since I mostly use linux and open source software.
Ah yes, for a start Tracker Control is even better than a Android firewall. If you don’t have F-Droid, an alternative PlayStore installed yet, you can also get it here: https://play.google.com/store/apps/details?id=net.kollnig.missioncontrol.play