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?
Exchanges have an important role in the development of Bitcoin popularity. With exchanges, people are easy in buying or selling Bitcoin. I can't imagine if we have no exchanges, people may get difficulty in trading Bitcoin. Bitcoin is also difficult to be popular since people may not trust Bitcoin if it is not traded easily. Some people may also think Bitcoin will disappear soon once the demand is getting less and less.
clearly bitcoin needs an exchange, especially the CEX exchange is very important to create trading volume as well as facilitating investors or traders to buy and sell bitcoin of course, also delivering miners who sell their bitcoins to investors so that bitcoin circulation continues to circulate to the public and with the exchange that is the beginning of popularity bitcoin started until today
Both CEX and DEX have the same function. Investors, traders, and miners need both CEX and DEX to trade Bitcoin. Some of them may prefer to use CEX, while others may choose DEX. Having 2 options should be better than having 1 type of exchange only.