At the moment the miners for a block are awarded 12.5 BTC. Every 4 years this value will fall by half. For example, let's imagine that the prize value is 1.5 BTC for each block and that BTC's value against the dollar does not increase. In such a case, mining will not be very profitable.
We will know about it in 12 years later when the reward is 1.5
BTCitcoin for every block.
The price should be increasing, especially in 12 years as the supply always decrease.
If the price increase $400/year than it will be great, around $5000/
BTC1.
At the same time, miners are also benefiting from the value of the fee. This time the fee values will increase. Then people will have to pay a high fee for bitcoin transfer. The biggest advantage of the Bitcoin system against banking systems was that they could shop without paying commissions to any brokerage house. If this happens, can bitcoin preference be reduced?
The fees will cover all of costs and profits for the miners as you said. People will pay same amount of but the value of bitcoin is higher than nowadays, well it consider high fee. Only time will tell, we just predict it that way.