Yes you can buy coin from exchange without doing kyc, but if you want to use P2P in the exchange you don't have choice than to submit your kyc. If you are playing to be buying coin in an exchange and you don't want to submit your kyc then I will recommend you make use of kucoin, kucoin exchange those not make it mandatory for users to complete their kyc but if you want use their kyc they have know the user to have scam. Also you can use decentralized exchange like pancake and Uniswap they don't require kyc.
Not all P2P platforms are no KYC, Binance P2P is the example of P2P platform that would ask KYC.
I think you don't get my Point, maybe you should try and read the post again, I said you can buy coin in some exchange but if you want to make use of any exchange P2P you have to submit your documents, If am wrong pls you can list atleast one exchange which you can use their P2P without submitting kyc. You can make use of kucoin exchange even without submitting kyc, but you can't access their P2P futures if you don't submit your kyc.
You're wrong to suggest Pancakeswap and Uniswap as the decentralized exchange to buy Bitcoin, there's no way you can buy Bitcoin using Pancakeswap and Uniswap since they're only use ETH and BSC chain. You're only can bought fake Bitcoin e.g. BTCB (Fake Bitcoin run in BSC chain) and WBTC (Fake Bitcoin run in various chain). It's not even a decentralized exchange, but a swap exchange.
Am not really sure about what you mean by bitcoin runs in different chains are fake, I don't know how true it is, but the OP mentioned coins and he didn't specify if he is buy bitcoin or not, the OP said coin so its not compulsory he buys bitcoin, and I can tell you if you don't want to reveal your identity to any exchange then its better you go for decentralized exchange.