There are still some reputable exchanges that have stood the test of time, but that doesnt mean that they can be forever reliable of our coins. But I guess people have been blinded by the promises of these centralized exchanges that they even trusted them with all of their coins. And others may also have no choice but to put their coins on the exchanges since they have no real knowledge and skills on holding them for long term in their own hardware wallet. And admit it, people have this mentality to just never want to exert more effort on their own, but only want to stay stress free even if it means trusting the exchanges for long term may mean losing their coins in the end.
True exchanges today offer lots of services such as staking, hedge funding, lending where if a customer avail can give him a passive income. We cannot deny that the offer is very attractive and rather than leaving our coins idle in our wallet, many tends to take advantage of the offer even though they know there is risk involved in their action. Just look at the Binance exchange, they offer services where we can earn profit, Binance exchange being reputable, gain people's trust so these people will not hesitate to send their coins to the Binance exchange and avail for their "profitable" services.