funny part is
take all the people that are holding bank notes and spend time working to get banknotes and assume that from no on no person enters fiat by buying bank notes.

well then people are now holding colourful toilet paper

..
here is the thing though.
before people had a market place to "invest" in bitcoin. people were using bitcoin.
heck. if you just let a few people want to use it for spending. people will. Laszlo in 2010 got pizza for bitcoin, yep before there was an "investment" exchange way of getting bitcoin, people found value in it and utility.
alpaca socks, bitcoin cupcakes.

so if you think that bitcoin is just "investing" to hold. your again ignoring the utility