Depends on the vendor for the specifics. In general, they don’t protect against an attacker who has gained persistent privileged access to the machine, only against theft.
Since the key either can’t leave the tpm or is useless without it (some tpms have one key that it can never return, and will generate a new key and return it encrypted with it’s internal key. This means you get protection but don’t need to worry about storage on the chip), the attacker needs to remain undetected on the server as long as they want to use it, which is difficult for anyone less sophisticated than an advanced persistent threat.
The Apple system, to its credit, does a degree of user and application validation to use the keys. Generally good for security, but it makes it so if you want to share a key between users you probably won’t be using the secure enclave.
Most of the trust checks end up being the tpm proving itself to the remote service that’s checking the service. For example, when you use your phones biometrics to log into a website, part of that handshake is the tpm on the phone proving that it’s made by a company to a spec validated by the standards to be secure in the way it’s claiming.
A lot of that information can be weirdly public. Looking up property records often comes with data about utility bills and taxes, and their payment statuses.