Talking about keys, I've seen the new trend of CEX like Binance,Butget and OKX incorporating seeming decentralized wallets into their deliverables and those wallets have keys, just like Reputable decentralized wallets too. I would love to warn anyone who surely loves his coins not to in any way preserve his coins in CEX wallets, Do not be deceived, they have control over your coins if you leave it in their wallets.
It is advisable to use Reputable ones which are open source like Electrum, Blue wallet e.tc to have more controls over your coins. Anything from CEX is not decentralized, no matter how they paint their story, BE WISE.
There are many cases where centralised exchanges have seized accounts of users for different reasons like not doing KYC etc.
You are wrong; centralized exchanges don't seize accounts of users who haven't passed their KYC verification. In some centralized exchanges, if you haven't passed your KYC verification, you can only withdraw a certain amount of bitcoin daily, and if you want to withdraw above that amount, that is where you will need to pass your KYC verification to enable you to withdraw any amount of bitcoin you want. While some centralized exchanges require you to pass your KYC verification immediately after you register on their platform before you can withdraw your bitcoin from their centralized exchange. What can lead anyone to lose his bitcoin on a centralized exchange is if the centralized exchange where the person keeps his bitcoin got hacked or when something bad happens at the backend without the person knowledge, such as when a centralized exchange is bankrupt. It's not your key, not your coin.
Is just that if you haven't done your kyc in most exchanges you won't be able to withdraw or buy , like OKX then if you haven't verified your account you won't be able to buy token nor withdraw,While some you can only withdraw a certain amount of token daily just as you mentioned.
Cex ain't bad though , just most people ain't using it right, to Me I use centralise exchanges to buy and hold with DEX , not just for safety reasons alone I believe aslong my funds is not in my exchange it will be hard for me to tamper with it, rather i should focus in accumulating more.