Kucoin was hacked and lost $300 milion of users assets. Collaborated with tether to lock usdt, collaborated with majority of altcoin to fork and lock stolen funds, collaborated with majority of crypto exchange so that they will not accept stolen funds and help in finding hacker (login logs). The rest of funds was covered from insurance.
I think that Binance is prepared even better. They have "safu" fund that collect 10% of trading fees to be ready for hacks and users losses due to exchange fault. 10% of trading fees ... Thats ~10-20 milion $ that was moved there just from yesterdays trading. They burned 500 million $ of BNB during last quarterly burn. Thats 20% of profit. Means they have ~4 bilion $ of profit annually. it means they can cover 1 billion $ hack with just 1 quarterly profit.
I'm not saying that holding crypto on exchanges is a good choice. I'm only saying that we have like 2-3 exchanges that are safe enough to call holding funds there safer than holding funds on your own wallet if you are not educated enough to know how to take care of it professionally.