So, I think the only platform here that is 100% anonymous when you are making use of it is localbitcoin.com, because with LocalBitcoin you just send to the buyer or to the seller and they don’t really know who you are, and before sending to them you just rely on the ratings and reviews that you have seen on their profile to do business with them. And your privacy will be maintained when you make use of this means.
LocalBitcoin now requires KYC to use, so it's not anonymous. Alternatives listed like LocalCryptos, LocalCoinSwap, LocalMonero, Agoratrader, etc. can be 100% anonymous, but only under certain conditions like mailing cash with a different or no return address.