Yeah youre right! no CEX is flawless Binance, OKX, Bitget, Bybit, Kucoin and many more theyve all had downtime before. Thats why I always keep accounts on a only limited cex, it’s just smart risk management and same way you diversify assets. Relying on one exchange is not good. But its always better to keep the funds or asset on a non custodial wallet for maximum protection.
To have top scale protection on your assets you should be keeping them on a private wallet so you don’t get swept away by unexpected losses when you have them on an exchange.
But for the OP it’s about trading not funds protection or security. The OP is recommending trading not only on one exchange and there is some sense in that.