Earlier quoted context omitted.
Lightning Network significantly reduces transaction revenue, so there will be dramatically fewer miners.
I don't think there will fewer miners. I think it's more likely that the price of Bitcoin would increase. There a lot of very large mining operations that cannot afford to scale down, and they won't sell their mined Bitcoin at a loss. If there are fewer transaction fees, this smaller amount of BTC would have to pay for all of the electricity that was used to mine a block. Maybe everything would change if the mining o…
The price will not be able to increase to the point that the mining block bitcoin reward itself will incentivize miners. As the mining block reward approaches zero, transaction fees will be the only way to incentivize miners. Since there will be fewer transactions, transactions won't have to provide a large fee just in order to get the transaction in the next block. The reduced transaction revenue will cause many miners to leave the network. Fewer miners will mean easier difficulty. This phenomenon stabilizes when mining is still profitable at the lower transaction revenue level.