This applies for people with or without collateral ~ which is making all the arguments related to collateral look specious in the extreme (as if they weren't already).
Tracking down debtors can be a problem in a country that doesn't even care to track down illegal alien serial killers ~ I can see where you're coming from on that ~ but eventually they trip up and the internet reveals their presence in some manner.
I think it's just a case of lenders not caring to pay the top dollar to the best track and trace folks. They imagine they can get by for cheap ~ maybe spin off that job to some call center in India or something (not to sound cynical, but isn't that what they do these days?)
Where can you borrow money at 4% without collateral? Or even 5%? I know of a few stock exchange listed companies that would like know your secret. In fact, it seems to me that you could make a bit of money by helping to connect lenders who are willing to make multi-decade loans at 4% and students who want loans at less than 6.8% (more or less the current private lender student loan rate).