Another big reason to switch to GNU/Linux.

Yes, phone number should be optional for easy contact discovery, not mandatory. As Threema. You have to provide your ID when buying a sim card.

1. Using software; 2. Telling my friends about it; 3. Helping others in forums; 4. Donating money, or bitcoin when available; 5. Running software that helps the network (Full Bitcoin Node, Tor Relay, SheepIT Render Farm - for Blender); 6. Translating.

Great decision to move to GNU/Linux. I used Mint and recommend it as first distro for a Windows begginer. I always use a USB stick for back-up. Enjoy the journey!