I think Crypto exchanges had some problems going on there that's why we are saying like this but Crypto exchanges still in the market so we cannot say anything negative for that if you die then we can say like that otherwise it will continuously running again and again.
I just see a topic in trading discussion which is about how many crypto exchanges got hacked since 2010 and the statistics are really terrible as billions of funds had been stolen and it is really a kind of panic I am getting because of how secured the exchanges I am into. But honestly it is not about exchanges are dead because as per you have mentioned they are continuously running one after one. It means we need to secure ourselves and we cannot be depending on them completely.
As per a recent study, most of the exchanges are faking their trading volumes just for the reason of attracting new traders. It may be part of their business to kick start in a highly competitive market but I'm not finding it is a good practice on a common trader's point of view. Because, many people are choosing exchanges based on trading volume as it will be the prime factor for having enough liquidity.
Cryptocurrency exchanges are not dead yet and it may not die completely for ever. But, it is time to learn our lessons so that we can secure our capital and then we can avoid big frustrations due to the collapse of any exchanges we are into.