No this is not possible. The user who connects to their Stripe Account to sell products on your site, would need to first setup their stripe account and have it approved by stripe for them to be able to begin accepting payments.
I cover this in detail in my Stripe Integration Course that outlines how to setup conditionals to determine if the connected Stripe account is ready to start selling.
Basically they can create the products without being ready to accept payments, but they can not sell that until their stripe account is ready to accept payments.
If you are however, referring to the issue of a ‘Guest’ buying a product, then no, they do not need to be registered on your app to buy a product.
I cover in the course how to set things up to track ‘customers’ in the application, but it is not necessary to have a user logged in to make a payment.