Scammed by a potential cash buyer but I don’t understand the motive

My partner and I are selling our house in New York state. We received a cash offer for our house 3 weeks ago that we agreed to. The buyer had documentation that showed his bank account had 7 million dollars (more than enough for our house). After we accepted he paid for an inspector but never put down the initial deposit of 10k.

Our lawyer and realtor kept asking for it and the guy just went MIA. Then we got an email from his “mom” through his email that explained that his car has been hit by a drunk driver and destroyed his laptop and phone. She gave a number to call but it went straight to voicemail. Our lawyer did some investigating and turns out the bank account is fake. We gave him a deadline which passed and the contract was voided.

We definitely got scammed, I just don’t understand what he is getting. He doesn’t have any of our personal info like SSN’s and all he has done is waste our time. Any idea why someone would do this?