Distributed systems where you own the data and there's no single point of failure.
> That's not how mining works. Layer 2 networks don't reduce the energy consumption of the Layer 1 network. They still produce 1 block every 10 minutes, and they'll continue mining as long as their costs are lower than the combined block reward and transaction fees.
I'm not an expert on the mining mechanics, I might be wrong but not due to the reasons you claim, transaction fees will approach zero as more people move into lightning and block reward will keep getting halved.