I followed the documentation on their website to install it on a vps

Same issue here

What is the reason not to connect it to the WiFi ?

Not really, buying 2nd hand implies that people still buy 1st hand. The second hand market is subsidizing the 1st hand market.

How do you tell your bank to use simplex to send you a verification code ?

I liked the fact that it is really easy to self-host.

I tried it with friends on discord and in 10min I had a vps with a server running.

The app is great and the server is very easy to self host.

A tablet ?

AirVPN is better option for torrenting since Mullvad stopped offering port forwarding.

I did that, I don’t have the time to change all my emails from my 15 years old Gmail account to proton.

So I’m just forwarding my emails from Gmail to Proton and started transitioning slowly. It’s not perfect but better than staying on Gmail.

You have some margin to work with. Of course it’s not going to be as effective than switching OS but you can use privacy focused firewall. For example Portmaster on windows or tracker control on Android.

These firewall will try to block as much telemetry as possible.

You should also be cautious about what you install on your system, opensource app usually have a better track record regarding privacy.