The issue of moving fast and some exchanges being closed, is simply blocking a group of people trying to access. To avoid this, we can only rely on decentralized exchanges.
This means that the exchange only works on the controlled smart contract
Definitely Yes mate, decentralized exchanges is much better than centralize exchanges. One of the main reasons why cryptocurrencies appeal to such a massive, global audience is because they can operate outside the reach of any one government, regulator or central authority. While this clearly raises questions on best practices to monitor criminal activity of funds, it also means that individuals can escape corrupt government regimes that have the ability to improperly seize privately owned assets. In a truly decentralized exchange, there is no way for any one person or entity to take control of the system, making it much more resistant to censorship, government interference, and power games.