Manual subscription payment

Currently, the subscription plan requires the user to set up a recurrent payment method for both credit card and PayPal. This can be an issue for users who don't want to set a recurrent payment or for users who are unable to (as PayPal enforces certain rules for accounts to use recurrent payments, even if the PayPal account has a sufficient balance to pay the subscription). This is not the case for cryptocurrency payments which are limited to the yearly plan, since recurrent cryptocurrency payments are not a thing. 

Because of this, I am lead to wonder why it's not possible to use manual payments for the other two payment modes. Users could simply be required to pay the fee upfront to access their plan for the next month and be required to pay again for the month after that once they want to. This would give users more control over their purchase and their budgeting, would improve transparency (since recurrent payments tend to be forgotten by users) and it would increase accessibility (some people are unable to set up PayPal recurrent payments because of their geographical location or because of their bank).