In the crypto community, however, the prevailing opinion is that the only correct way to buy hardware wallets is to buy directly from the manufacturer. We can discuss whether this is better or worse than buying from authorized resellers, but some people have no choice but to order directly from the manufacturer. Regarding dedicated mailboxes, I know such things exist but I believe it is not a free service and something that is known to everyone.
I’m familiar with Links selling Ledger HW, as well that Trezor can be purchased in Bitcoin Store physical offices in ZG&ST.
Prevailing what?
This is official Ledger retailers listed on their website.
https://shop.ledger.com/pages/retailersor become retailer and Ledger Partner yourself:
https://ledger.typeform.com/to/nIcfT9If they can manipulate and change ledger wallet, so can your mailman and customs.
If you are so concerned about that maybe go directly in their factory.
Dedicated mailboxes are not free, but people who order things online and care about privacy all know about them.
It is not top secret in the western world...