No, it's security by intrusion detection, generally. HSMs are designed to be boxes that it's very hard to get a secret out of with physical access. TPMs generally aren't the most paranoid version, but it gets more expensive and less practical as you go further (e.g. a large box which has a battery backup, keeps the secrets in RAM, and will wipe them as soon at it detects any funny business. These are DIYable, but the list of tricks by attackers is long and it's hard to cover all of them at once). A TPM is generally somewhere in between that and a regular micro with no particular effort to prevent readout of internal storage, in that they are small, can persist secrets without power, but are still difficult to attack physically (~maybe at the level of advanced criminal organisations, ~probably at state level if they're willing to spend some money on it, even absent a backdoor).