We are entering a very interesting phase of our Bitcoin experiment, where we will soon see if "Miners fees" will be sufficicient for miners to continue mining. We all know that the Lightning Network is way better for people to use, because the fees are much lower and the transactions are much faster.
Now, what will happen if the Lightning Network adoption increase so much, that we hardly get any transactions on-chain? Will the few transactions being done on-chain be enough to reward miners? (We hope that the price will go up, so that the few Satoshi's are worth the hashing power used to get it)

I was just thinking about the time when all BTC will be mined. I know we all won't live at that time but I'm wondering... If the fees should cover the cost of mining, won't they be too high? I'm not sure how many transactions fit in one block, but if today a block reward (6.25 BTC) is around $270.000 in fiat, won't fees cost too much once all BTC is mined? I mean, that means fees of all transactions in one block should cost around $270.000.
Sorry if what I wrote is bunch of nonsense. I'm just trying to figure it out...