I still stand on ‘no exchange is perfect’ but having a backup to spread your activities on would definitely save some stress when the unexpected happens which is why OKX is my third one. Just like having a diversified portfolio and having multiple investments basket, having different exchanges is a good decision in my opinion. Do you also use multiple exchanges or you stick to one ?
You're right about using multiple exchanges, but I'd add that the choice of each platform should be for a specific benefit, not just for diversification.
I also used OKX for a while, right up until their founder disappeared with the wallet keys and they froze withdrawals for a long time. I started way back with BTC-e, but luckily left before the US seized their servers.
These days, my setup is more strategic. I use Deribit for options and futures, which helps me hedge my spot positions. For buying actual crypto, I use the Cryptomus wallet and exchange because they have the lowest fees and many of my crypto business partners are also their clients, so I even get cashback