i dont understand why bitcoin has to be just base on people perceive value of it. and for someone to just artrarily fix the supply of them at 21 million doesn't make any sense. it should be able to contract and expand the # of bitcoins in existence. but because bitcoin is design very simplistically it is kind of like monopoly money. not backed up by anything.
The value of things is always subjective; it may vary significantly from one person to another. Some people don't value bitcoin at all, claiming that spending energy on its mining is a waste of resources, whereas others may value bitcoin because it allows them to make unstoppable transactions, which can be settled in seconds without the participation of any trusted intermediaries. A fixed total supply is one of the main features that make bitcoin valuable to some people simply because these people understand that no other assets in the world have similar peculiarities.
bitcoin doesn't get used anywhere for any purpose. it's just imaginary.
If it is imaginary, then you can use your imagination to make yourself rich by imagining thousands of imaginary bitcoins. If you can't do that, then there is something wrong with your conclusions.
Op is missing on a fact that bitcoin as a production cost as well.
Production cost doesn't invest in bitcoin value at all, miners produce bitcoins because they are valuable, not the other way around. If you invest your time and labor in something no one needs, this thing will have zero price despite production costs.