Bitcoin doubles in price for absolutely no reason over the span of a few days, then drops 25% in the span of one single second on no news and for no reason, but yea, it's not an entirely rigged, fake market at all.
of course, there is manipulation, no one denies this
that doesn't make btc worthless, we still like the technology, and the idea of being your own bank and being able to send or receive money anywhere, anytime, in few seconds, for very low fees, even if it's not entirely decentralized
so unless you have a better option (silver or gold are useless), we will stick with bitcoin