> So the secure element ain't tampered with.

Back in the day, RSA SecurID hardware tokens were completely physically sealed, with no room for a backdoor. Tampering with them in any ways destroys them or makes it physically obvious. That's a physically secure design. This Ledger thing looks more like a consumer toy.

Not to contradict your point, but in 2011 RSA's SecurID backend servers were hacked. TOTPs require shared secrets, and their server had all the secrets to the SecurID keyfobs they managed. Security is hard.