What we have right now is either not decentralized at all (despite being called that) or is partially decentralized and using it is a hassle.
I don't disagree with that, but we already have Bisq, which fulfills all those criteria and is truly decentralized. Adding more exchanges doing the same thing will only serve to spread the already low DEX volume even more thinly. Bisq can be used by anyone, at any time, anywhere in the world. Adding more DEXs doesn't solve the issue of people not using them.
we have to improve the user experience so that they could use it just as easily as they use CEX.
I don't disagree with this, but it mirrors the old fiat v bitcoin argument. How do you get people to start setting up their own wallets and storing their own keys when they are so used to just swiping a bank card and having a bank deal with all the complicated stuff? How do you get people to start running their own Bisq client and setting up their own trades when they are so used to just hitting "buy" and having a centralized exchange deal with all the complicated stuff?
Using a DEX is, by definition, always going to be more complicated than trading on a CEX, and it can only be simplified so far.