Ftx was a top exchange, but it went bankrupt due to mismanagement, Binance is a top exchange, but it has been hacked in the past, Bybit is also a top exchange, but not so long ago they were hacked and lost $1.5 billion dollars, i can give you many more examples of this. Of course i know it is best to use "top" exchanges, but i disagree that it is unlikely they get hacked, many of them do not pay as much attention to security as you think they do, they are all about making money and that's most important for them.