So in crypto bitcoin is the most important and valuable coin for now as we can say that in the future bitcoin will use for many purposes so it will make bitcoin more expensive.
What makes bitcoin expensive is its demand and the supply. Because the supply is going to be limited after a certain period the demand will rise. Now whales will pump coins and dump them making the markets crash. But that is least important when we consider the ideology behind bitcoin and crypto. So those who believe in the future of these assets are holding it and actively trading it.
I don't think prices are always manipulated by someone. do you know bitcoin marketcap reaches billions of dollars? who is the person who has that capital and wants to take risks by endangering their money to manipulate the market which is not necessarily possible. but I do not rule out the possibility of manipulation sometimes happening
The marketcap is not real. It is at least 50% excess of what is shown in coinmarketcap. One of the major reasons is unlisted trades which happen and p2p trades that go on. Its not possible to track every one of them.