As a millennial, this is how my friend group works too. Figuring out who owes what is the hard part usually.

The trick with split-bills type of apps is that the usefulness isn't actually in splitting a bill, but instead the main value is in creating a long term ledger that can tell our group who needs to pay the bill today ;)

I think both things are useful, this one for one-time payments and the case you mention for tracking expenses in a group that are spending together frequently.

Is there a way to incorporate that in your solution?

Could be extended to have a split where multiple participants can track their expenses but is not implemented at the moment.