I know Lending Club and Prosper are very popular so I could see some interest in an crypto based platform, however like you point out every state has it's own money transmitter and money services business laws which would make this project impossible to pull off legally.
Furthermore as someone who has actually used Lending Club it absolutely sucks. They show very high rates of return, however they purposely don't re-calculate it after your chargeoffs are applied so while they may show me earning 8% in reality I'm earning more like 1.25% after chargoffs.
Whether you pick "D" grade credit people or "A" grade credit people you still get chargeoffs. I suppose maybe its better than interest paid in a savings account but your tying your money up for anywhere from 3 years to 5 years depending upon hte loans you pick and the returns are pretty pathetic so while it's cool they are using crypto I still wouldn't use it.
Yeah I looked into Lending Club and Proper a couple of years ago because I thought they were doing something different but in Arizona you can't even invest in loans. You can only buy notes on the platform and from a borrowers perspective it didn't look that sweet. I still get letters saying "Your Approved!!"
I was in bitlendingclub before they folded and lost about 3 of 5 total bitcoin before I pulled out. The vast majority of borrowers actually did pay off their loans, but it only takes a few to wipe out your profit on tens or hundreds of loans(assuming you are trying to be smart and do tons of microloans.)
Another big issue is that when someone defaults, how do you go after them? If they are in your country and your country has a decent legal system you could try and get a lien put on them if they won't pay and pray that you eventually get your money back. However, how do you think you are going to get your money back from borrowers in second or third world countries? You're not!
It is a tough problem to crack and if anyone ever does figure it out they will become filthy rich. I just don't see anyone who has the solution yet.