There are many people on here smarter than me on monero, but I can tell you how I buy xmr for fiat without KYC. P2P using RetoSwap (previous haveno-reto), there are a few options for how you send fiat, some more revealing than others, but ultimately you're revealing that info to another individual and not a company.
Depending on your threat model you can buy completely anonymously by sending cash by mail and not including a real return address, at the risk of your cash getting lost in the post.
