Centralized exchange and Decentralized exchange have advantages and disadvantages. So it depends on us as users, I think both are needed in the crypto world. For developers, it seems that a decentralized exchange is more appropriate, because high listing fees are not applied.
So it's easier for developers to register new projects on decentralized exchanges. Then for investors or traders, it seems that centralized exchanges are much better, because there are many choices of quality projects. And usually have low trading fees and high liquidity, so daily trading on centralized exchanges is much more profitable. For now I am more comfortable using centralized exchanges than decentralized exchanges.
The part that says we need both of them are the only thing that matters here. Both have their ups and downs like you said, which means that if we end up not caring about the results of just one, then we are going to be stuck with the other. So, it is better to focus on the thing we already have which is best of both worlds.
If you need to use a DEX then use one, and if you need to use CEX then use one and it will help you out in the long run to go on like that. I use metamask and pancakeswap and uniswap along with how I use coinbase and binance all at the same time and have money in all of them. Why? Because what I need at that moment matters to me and it could be different stuff.