The value of cryptocurreny changes because of its volatility therefore if there are some changes in the market then the price would surely changes so if prices changes then there will a lot of people who will take the opportunity to earn more money that's why people use crypto for different purposes such as for storing or profit as an example. Anyway, even if the purpose of bitcoin isn't used all the time but there are some people who really used it for its intended uses.
You confused about value and price.
Value does not come from price while price comes from value. Without value, price will be zero no matter how scammers want to build up price, it can be high and expensive for a while but eventually will fall to zero.
Value comes from other things that must be fundamentals to make that blockchain, that project, that cryptocurrency has intrinsic value while the value itself can be assessed rightly or undervalued by investors and market.