lol ok
You have no evidence your private key is the only key that can spend a utxo.
This property of bitcoin depends on the ECDSA encryption it uses being mathematically sound and the implementation being correctly coded
YOU *TRUST* THE BITCOIN COMMUNITY WHEN THEY TELL YOU THIS IS SO.
YOU ARE ALREADY RELYING ON CRYPTOGRAPHIC PRIMITIVES YOU DON'T UNDERSTAND.
YOU JUST REFUSE TO ACKNOWLEDGE IT.