but it needs to be secure and allow for anonymous transactions, and not allow for tampering with the ledger. Bitcoin has failed on all three accounts.
Lol what? No legitimate bitcoin critics make these claims against Bitcoin. The ledger is immutable and the transactions are pseudo anonymous. In fact your typical bitcoin critic lists these as downsides ("no way to reverse mistakes" and "cannot prevent money laundering") right after the criticisms about energy consumption.
You legitimately have no idea what you're talking about.
You said the Bitcoin ledger is mutable. It's not. You said Bitcoin isn't anonymous and that's mostly true because it's pseduo-anonymous which can be fully anonymous if you want it to be.