Mortgage, auto, personal loans, medical, so many things smart contracts can fulfill. 

Doesn’t have to be on Ethereum but they are the best to do it. 

I just won’t own any lol  

 Smart contract sounds cool  

 What they do smart contracts for those domains  

 I’m sure they will. Probably layer 2 or 3 bitcoin. 

I know Stacks has smart contracts on Bitcoin but not as popular yet as ethereum