Bitcoin is scarcer than you think. There is only 5% currently available on exchanges. The other 95% is in wallets with probably 6-8 million coins lost forever. Roughly 90% of all bitcoin has already been mined and it will take another 100 years to get the last 10%. If governments and institutions start buying it up in large quantities the liquid supply will drop quickly.

Just simple math says that there will only ever be 5-10 million whole coiners and probably much fewer.