It's true that people are holding other currency such as gold, silver and other valuable resources but it wasn't meant for a transactional purpose, but as I know Gold, Silver or diamond as we know is basically for investment. Please do not quote me wrongly, I didn't say bitcoin is not meant for investment or worth for investment, but what I am trying to deduced is that people are now now channeling efforts on the investment purposes than the transactional aspect of bitcoin.
Yes gold, silver, and diamond are now basically for the investment but long years ago these especially the silver, gold these are also used for the transaction. And If you look back to now these you will also see that lots of people and the countries are holding the USD because the inflation rate of this quite low than others and also this has kinda global acceptance. So in the case of Bitcoin this is better because here there is no inflation except the volatility and there is a option for holding so why not we hold them like we save money at bank and when we have the needs we also used that. And about the transaction of Bitcoin it won't be stop it will be increase day by day. But I want to also agree with you if a person think that bitcoin is only for the investment then he is surely wrong.