I wonder how many companies with closed-source HWs would not sacrifice their clients for millions of bucks coming from IRS. In an open-source world, it is indeed very weird to sell a partially closed-source product. But since authorities have easy access to very large fundings, a $10M secret contract with Ledger might actually sound good enough for them to allow backdoors in their HWs, if they haven't done it already.
It is enough for them to have just one dirty worker in this hardware wallet factory who will add some hidden backdoor and nobody will ever know that something is wrong.
Secure element will not help you in this case, and NDA will prevent them from saying anything about that in public, so they don't need to pay millions of dollars at all.
the irs doesnt need private keys or the seed to achieve their main objective; all the need is a list of addy you control. at that point they have all the info they need as they can then monitor those addys.
Oh but they do need your private keys and passphrases to access your funds and confiscate them whenever they want, because they probably have a bunch of hardware wallets full of treasure just collecting dust in their warehouses.