Must Cardano be acquired via KYC exchanges? Is it available through any DEX?

₳ is available on all dex's on the Cardano Blockchain. It depends what blockchain the dex is on that you use. If it's not Cardano, at most it can only be a wrapped ₳ token. So it's not whether a blockchain has a token called ₳ on their dex.. it's whether it is truly wrapped to ₳ and whether there is a route to swap it to ₳ on the cardano chain