Whooaa. That escalates quickly. Well, bitcoin's price really is unstable but it goes higher than being going low. $5000 is big pricw for Bitcoin. Maybe 10 years, for that price. Or maybe 15 years. Many things can happen and it may affect bitcoins price. So saying that, lets aim first for $1000 price. That is really a big price dont you think?
If bitcoin takes 15 years to get to 5K, it would probably die beforehand.
Why? We have a difficulty mechanism that splits the block reward approx every 4 years.
In less than 16 years block reward would be 0.78125 BTC, which is 1/16 of the current. 767X16=12272.
EVEN if difficulty does not increase at ALL (fat chance), then prices would have to adjust upward accordingly or nobody will maintain the network.
tech improvement (chip going 14/16>10>7nm) and difficulty rise due to an increase in hashing would cancel each other at best. This did not happen before, which suggests a potential need for even higher prices in that timeframe.
Maybe but don't forget that any parameter can be changed if need be including difficulty adjustment, mining algorithm, etc.
If Bitcoin becomes mainstream and widely used anything could happen really if issues as you describe were to happen.