By "follow best practices", you mean "not using Bitcoin", right? That's the only way your words make sense. If you pay someone without spending the full UTXO, you're always creating some sort of a pseudo identity. Say you paid for a domain online, then bought dinner using the change. Your face is now linked to that domain thanks to CCTV cameras. If you paid for a VPN, then sent the change to someone on Nostr, your social graph is now linked to your IP address. It just takes some digging and a few subpoenas.

Bitcoin is good and useful. But you have to acknowledge its flaws. Otherwise, we're no better than a cult.