Bitcoins can exist without exchanges, but would you support the argument that the existence of exchanges are among the factors facilitating the popularity and accessibility that people have to bitcoins?
It would be shortsighted to not recognize that exchanges have accelerated the rate at which bitcoin was adopted and they have increased its popularity as an asset to hold and to trade all over the world.
But we cannot deny that centralized exchanges have also brought their fair share of issues, one of the most obvious ones is that now many people prefer to keep their coins at exchanges so they can trade and invest as soon as there is a big news, but this compromises significantly their privacy and the true ownership of their coins, two aspects which are incredibly important and which are disregarded by a great deal of traders now.
it's true, most people put their assets on the exchange, they see the exchange as a place to keep their assets so they can quickly use it whenever there is a signal for see them make a profit. here, we often advise each other not to put too much money on the exchange but I have seen many people put millions of dollars into it to trade futures and they even hang orders overnight, weekly. today's investors no longer care about privacy, what they care about is profit, and how to make as much money as possible.