I posted this on another forum:
I use proton username and password which has not subscribed before and it brought this up on my mobile phone:
Because I did not subscribe and it brought up 'Updating your account' and did not update anything nor load any wallet. So no wallet until you subscribe.
I think if you subscribe, you may also be able to access their paid VPN (but I do not know) and their other products and services. But I can use other reputed noncustodial wallet like Electrum, Bluewallet, Sparrow, Unstoppable, Metamask and some other wallets without even using email and password and and they are free.
Be it open or close source, I do not recommend web wallets. I prefer a wallet that I do not need email, username and password to login. Just seed phrase or private key is enough to access my coins.