I don't see how your earnings could be locked in by Stripe. There must something in your country's government that is preventing the payment. Once you sign up with Stripe payments are automatically sent to the account you linked. You don't even hve to request it. I'm not sure why you're having a problem.

Also, I think Medium is trying to address this with the TIP feature. You don't have to be in the Partner Program to activate the tipping feature. However, if nobody wants to tip you, there will be no earnings. I am on several platforms that have a tip button. But only once have I received a generous tip.