As others have said, it was covered in the article. In a word: attestation. In more words, the CPU TPM contains a key signed by Intel / AMD or whoever, and ca

As others have said, it was covered in the article. In a word: attestation. In more words, the CPU TPM contains a key signed by Intel / AMD or whoever, and can prove it. swtpm doesn't, and there is no way to fake it.