It supports substantially more complicated movements of money. Stripe Connect is basically "Bring your own Stripe account. We handle the API integration for you." This lets you do things like (hypothetical case for Airbnb-clone) "Pay the room lister 90% of the amount charged 5 days after the later of 'satisfactory feedback received from renter' or '10 days after checkout'. Then, pay us our 10% fee for enabling the transaction."
Bonus: with this, the lister doesn't need a Stripe account and will perceive all of their interactions with money being handled by you or their bank. This means you don't have to, as a part of making the sale to them to list their room, convince them "You should really open a Stripe account."
With Stripe Connect, your users have to have Stripe accounts. This makes sense for, say, Squarespace, where their users are likely to want to manage the business themselves: logging in to their Stripe account, watching their analytics, providing refunds, handling customer service, etc.
This is designed for cases like paying Lyft drivers. The drivers don't really care about the internals; they just want money to appear in their bank account.
Each of your marketplace customers would need their own stripe account (we do this now). This would enable a single stripe account to be used for charging the cards, and your app controls the transfer of funds back to the marketplace vendors
