From 2099 till 2140 (when the last satoshis will be mined) there will only be one bitcoin mined. By the end of the century, supply is virtually fixed and limited to the maximum of 21 million. For the following forty years, miners will be mining only one bitcoin...
With most transactions (and most tx fees) being forced onto second layers, it will be interesting to see how this impacts miner incentive and their desire to secure the blockchain.
My best guess is that by that time, Bitcoin will have become a minority player in the space due to its inability to evolve.
I think it is still very early to give a final statement about Bitcoin's inability to evolve. There is a possibility that Bitcoin might become a minority player but
who knows what surprises these Bitcoin developers have in their stash in order for Bitcoin to be that attractive for miners to stay on Bitcoin Chain when that time comes. Bitcoin supplies might have fixed supply but people and developers around it are constantly evolving and changing and continuously designing plans so we just cannot look at Bitcoin as stagnant water.
With most all Txs being pushed out onto L2, maybe we have chance of winning miners using their altruism.