We might think several scenarios that will happen to bitcoin incentive in terms of mining as time goes by. When the price of bitcoin goes high, then we can expect that the incentives of mining will be big as well. But we cannot deny that there will be possibilities such as hoarding of bitcoin might happen. What will happen next? The supply of bitcoin will be lessen and miners will surely cannot gain the amount that they are expecting.
I think that if people hodl bitcoin (do not transact it
at all) then after the coinbase reward for miners has dropped to 0 they would stop mining (because it wouldn't be profitable for them anymore), rendering in effect the whole blockchain obsolete. This will never happen though, because the moment it is starting, the price will start dropping and people will start selling, in effect providing the benefit for miners all over again.
So in effect it will be a case of dynamic equilibrium.