Today, these are the two largest exchanges with huge liquidity, DEX will not replace them, which means you will pass KYC anyway.
A DEX will replace them for you if you want it to. I've never so much as registered on any centralized exchange and I've certainly never completed KYC at one, yet I would bet that I buy, sell, trade, and spend bitcoin more than ~99% of the user on this forum. I certainly wouldn't be giving up all privacy for the sake of $20 worth of some shitcoins (never mind the fees I would pay to the centralized exchange just to be allowed to swap that shitcoin in to bitcoin and withdraw the bitcoin), and I'm certainly not letting Coinbase sell my data to a data broker and risk identity theft for $20 of some shitcoins.
I believe he didn't even use that DEX or instead using a fake DEX e.g. pancakeswap, uniswap, shitswap etc lol.
Actually I wonder why people really need Bitcoin ASAP, like they didn't have many times to wait even for few hours or a day, if you're trading with BTC/USD or Euro pair your orders on Bisq would be completed for few hours or a day. I think when you're want to start invest on Bitcoin, you're only use your extra money, not all of your money including your emergency money.
Personally I prefer to wait more longer to complete my transactions rather than waiting my coins will be unfrozen after I submit my KYC, the another thing is waiting to be completed KYC is long too.