Cons
Costs money (typically $100)
Can be lost or damaged, but has backups.
Needs backups of seed phrase
Needs backups of seed phrase is not a con.
Of course it is not a con, but it is something to manage and pay attention to.
But I see your point, and I will try to better describe this concept.
According to what I saw about it online, before the seed phrase backup is done on the cards, it requires Internet connection. Is it true? For the seed phrase backup, it is displayed on the phone. The phone that can mistakenly be online or that people might not on the airplane mode while setting it up.
I didn’t try the seed option. I tried only the seedless way.
I think my device actually was online when I setup that. For sure I didn’t remember any advice of getting in airplane mode.
Having said that, this wouldn’t be much more added security, if Tangem were a malicious organisation, nothing would prevent them to make the app (which is
open source and audited, btw) to transmit the seed at a later stage.