Another alternative to fully preparing a separate billing pipeline (which could be quite a lot of work) would be to add a “free switch” you can hit which allows users to sign up m, have them confirm a plan, and gives them access to the product, to be billed at a later date.
That means that in a crisis you can still sign users up, and take a few days to sort out the billing situation.
Could save some time up front, and if Stripe ends up never causing a problem you didn’t waste effort on unneeded complexity.
Adyen is a possibility. I never used their services so I cannot say if they are a good alternative. But they exist, and some people swear by them.