There are stupid ways to use Proton, just as there are stupid ways to buy and use Bitcoin. 
But there are many smart ways to do this. Then there's Lightning, then there's Cashu. 
Less private than credit cards LOL.

anon

Both name and surname are connected to your centralized exchange.

But that information is not directly visible by merchant. Needs chananalysis, which gives some uncertainty, unless you paid directly from the CEX.

But CEX is not a requirement to use Bitcoin, I have seen totally computer illiterate people, not geeks, buying Bitcoin with cash peer to peer.

privacy

Protonmail is now fully compromized

> Both name and surname are connected to your centralized exchange.

But that information is not directly visible by merchant. Needs chananalysis, which gives some uncertainty, unless you paid directly from the CEX.

But CEX is not a requirement to use Bitcoin, I have seen totally computer illiterate people, not geeks, buying Bitcoin with cash peer to peer.