These transaction fees could potentially rise to many thousands of dollars or more per block as the number of transactions on the blockchain would eventually grow.
It will still take more than a decade before all bitcoin will be mined, we do not really know what could happen, but I do not think the transactions fee can be as high as thousands of dollars because:
First, bitcoin transaction fee may increase to an extent that more people will prefer to use lightning network which makes the transaction faster and at low fee charges, this could be one of the solutions to increasing bitcoin transaction fee.
Second, there could be another bitcoin improvement proposals that could gain bitcoin community interest in such a way to reduce the increasing bitcoin transaction fee.
But I am not disputing the fact that bitcoin transaction fee will increase, it will surely increase because the adoption of bitcoin will increase, the price will increase and this will results in transaction fee inceease, but increase to as high as thousands of dollars will discorage people which I believe is not possible.