There are 3 main ones with a contract where you pay for a monthly plan and stuff. I want to avoid this.
Then there is 3 prepaid SIM card options which are basically forks of main cellular providers. So I want to pick one of these 3.
But I don’t know which one of those would be best for privacy and which one has the best practices. What should I do? How do I compare them? It is pretty hard for me to compare them and understand privacy policies and stuff.
Usually with prepaid SIMs you can pay with cash when you buy them. If payment history is something you’re concerned about then maybe that’s a better option. However you will have to renew or top it up every month, and depending on the provider you may have to do it online, which could require a card payment. Depends on your threat model whether you’re okay with that.
As for best practices, I don’t think there’s much way to tell without reading the privacy policy. The sections you usually want to look out for are about “data we collect”, " data we share" and something about if they inform you of updates to the privacy policy and ToS.
Unrelated to privacy, but also check out reviews for the provider’s internet speeds and customer service, in case you have problems. That should help narrow it down further.
Seeing as most of your internet traffic is routed through the provider you choose, there’s not much you can do except trust them and their privacy policy. If you’re really concerned, you could always use a VPN provider that you trust instead. Some good ones are Proton VPN, Mullvad and IVPN. If you choose to do that, then it doesn’t really matter too much which provider you go with, except maybe the internet speed you get.