Why do you say TEEs don’t work at all?

TEEs, as they're marketed, requires a true black box. True black boxes do not exist, as a property of the rules of our universe.

You can ALWAYS break them, it's just a matter of cost, even assuming they're perfectly designed and have no design/implementation flaws. And they're often not perfectly designed, sometimes requiring no physical hardware tampering.

The point of security efforts is to make an attacker's life harder, not to construct perfect defenses (because there's no such thing, as you've noted).

TEEs make attacker's lives harder. Unless you can find a way to make your interposer invisible and undetectable, the value is limited.

Quantum mechanics with its non-copy property implies that a true black box can be created.