If just feels so disingenuous to read this statement when items were already addressed as not being sufficient, but seemingly ignored.
Proton VPN - Leaks your IP address
The use of “Cryptocurrency” is effectively just Bitcoin. XMR was never implemented to be able to fund your account with XMR credits, and is not available for most service plans. Only Proton Pass is available at a significant mark-up.
The vast majority of cryptocurrencies operate on a transparent blockchain, meaning that every transaction’s details are public knowledge. This includes most well-known cryptocurrencies like Bitcoin and Ethereum. Source
In my opinion, a recovery email could be stored more securely. I guess there is no reason to re-iterate the very well authored dark pattern post, but I’ll link it once more.
Even if you do decide to switch to BTC or Cash as a your new payment method - it’s not possible to delete your credit card while still subscribed.