To be honest, marketcap has less thing to do with trading anyway. It is not about the marketcap will grow few years later or the value will increase after the halving or whatsoever but it is about the movement of the price, the fluctuation of each price .
Even if BTC value were to fall into 1 cent / BTC if there is still a movement in this then BTC is worth to be used for trading , however even if we see $1000 / BTC but if the value is constant without any movement at all then it cant be traded at all (unless someone or few people manipulate it to make it looks fluctuative)
But if the value of bitcoin will drop in cents.
Many users will not using bitcoin because of its value and many will disappoint when its happened.
It is not about the value or the usage of
BTC to begin with. It doesnt actually important in trading, whats important is the movement of it and that is where trader got its profit and not about millions of people to use it. Of course it will be useless for trader if there isnt any movement eventhough millions of people use it or the mass adoption is happening though
Why would you not want to use it if the value were to fall into cents (which is unlikely) ? The feature as well as the technology stays the same even if the value gonna drop in the future anyway.
BTC is still
BTC despite the value drop or crash but ofcourse most people will jump out of the sinking ship
But if you will notice that people want more money and they not contended on what they have or how much they can earn. They want more and they don't like a small value for a long time.