This is not how it works at all. Holders/ "hoarders" of Bitcoin do not decrease the utility of the network one iota. Because there is infinite divisibility, if I want to take some fiat and move it to another place via the network then return it to fiat at some arbitary price at a point in time, the fact people are holding (even if 99% of all Bitcoins were locked up) makes no difference to the utility of the network. All that has happened is that the decimal point has moved.

What is happening is that supply is reduced. Demand has presumably remained the same as it otherwise would have been, and as a result the price rises. This is great for people holding, and it encourages more saving - but the rising tide is lifting for all boats here.

For you who is just temporarily utilising the network, the fact that the price of Bitcoin might be ludicrously high (in your opinion) doesn't change the fact that you can utilise the advantages of a decentralised liberated money for your wealth movement at the same cost that it would have been if Bitcoin were at a low price.