that is true, we can't get an absolute assurance from all these exchanges, whether they are at the top or not. but one thing you can safeguard your funds is get out your funds as soon as you finished trading. secure it in your own wallet where you have full control of your funds.
having proof of reserve of funds won't guarantee that they will rug pull or do something unexpected. they can easily give the wallet address having their funds but they have full control of such funds, so they can still do what they want to do with their vault money.
While measures like proof of reserves and financial capability are positive steps toward transparency, they do not provide an absolute guarantee against all risks. Even with such assurances, there is always a possibility that exchanges could engage in unexpected or unethical behavior.
One of the most secure ways to safeguard your funds is to withdraw them from the exchange as soon as you are done trading and store them in your own wallet. By using a hardware wallet or other secure cold storage solution, you have full control over your private keys and funds, reducing the risk of potential losses due to exchange-related issues.