The maximum number of bitcoins that can be issued is fixed.
Eighty percent of the coins have already been mined.
What do you think will happen to the price after all the bitcoins have been mined?
The miner can stop mining Bitcoin if they won't get much profit like halving rewards.
I don't know, maybe the developer team will make a new pathway for the miner by which they will get benefited and continue mining. or it can happen total supply may be increased, only time will tell. But the reassuring thing is that this is not going to happen very soon, it's too early for such a discussion.