Privacy is a necessary feature in my opinion, but why hasn't Monero become a main coin?
One of the things that I've noticed about Monero is that it has been removed from a lot of big exchanges.
My guess is that some people want to have certainty that they will be able to go to any mainstream exchange in the future and exchange their crypto for other type of money.
Having Monero out of the big exchanges will probably not incentivize some of the big players, therefore reducing the potential price.
One of the Marin why exchanges keep removing cryptocurrency projects from there platforms is because of liquidity.
There are project that. An cause exchanges to lose money if they eventually crash out due to low liquidity or no liquidity at all.
Liquidity is what keep projects going making it to be volatile and having the ability to make investors make or lose money at the same time. Any project that has been noticed that it has not even been doing well could easily be removed.