I think it answers the question pretty well. They said it doesn't do anything different, and it was a missing product in their lineup that customers were expecting. Since that product is bundled to your payment processor, if you were with Stripe instead of Square or PayPal you didn't have access to those kinds of loans/cash advances.

They edited their comment to a completely different answer, without noting so. The original was just a marketing blurb.

Stripe has exactly what Square and PayPal and many other offer. Similar rates, process, terms, etc - no outsized compelling reason for one over the other (similar to CC rates)