The question is: where is the catch?
As long as you buy from reputable shops, or, even better, from those companies' official shops, there's no catch.
Some HW have no screen, some HW work with NFC only, and those go even lower than 39$. Some are Bitcoin only.
Make sure you know what you're buying. There's a topic that compares most HW very good, search it up.
For example, if you guys were choosing a new wallet now, and came to a shop where all open source hardware wallets are represented, would you purchase an inexpensive convenient beautiful "exotic" wallet? Or would you purchase one of the same wallets you used to consider, like Trezor/Coldcard/Bitbox02 ? Why?
I have a Ledger Nano S. When it's going to die, I will most probably not buy Ledger, unless they do something so great I'll forgive them for their many late mistakes.
One device I'm eyeing is SeedSigner. Pretty cheap, smart and I like it. Everything is open source there (OK, excepting the RasPi itself). I like the idea of using images to transfer the information.