Binance, FTX, Huobi and Okx are the leading exchange that least can encounter bankruptcy among all the CEX available on crypto right now.
There's no best exchange. But i agree the mentioned exchanges above at least you are insured that even a hacked incident happened your funds will stay there.
Of course, when you consider such statements you're disregarding the risks and safety measures of "not your keys, not your coins" idea.