There are trillions of transactions which take place annually. Bitcoin can do about 200 million layer one transactions in its current form. 

FedWire is a interbank settlement network run by the federal reserve, which did 200 million transactions last year. That is the best comparison to Bitcoin in terms of volume and final settlement assurances (although it’s nowhere near as final, nothing in fiat is irreversible).

You can use Bitcoin however you wish, so I’m sure there will be people like you and me who buy houses or cars on L1. In 50 years though, L1 will likely be dominated by financial service providers and banks settling between each other, or fedimints and other Lightning providers opening and closing channels. You definitely won’t be buying cars on L1, and you probably won’t even buy a house on it either. 

 Fascinating!