What?!
No, hardware wallets don't have more attack vectors, because their only purpose is to work with cryptocurrency transactions.
Software wallets are installed on multi-purpose devices like computers or smartphones that by definition have multiple time more attacks vectors than hardware wallets.
Not to mention all the risk with malware, viruses, keyloggers, internet connection, and bunch of other issues that don't exist on good hardware wallets.
Hardware wallets have been
known to have physical vulnerabilities, and someone might be more inclined to leave them lying around unsecured. A software wallet, you technically only need to save the seed, and generally you'll be warned to secure that pretty well. I'm not talking about a software wallet connected to the internet, I'm talking from the point of view where you want to generate an address, and just receive Bitcoin to that address. Since, with a hardware wallet you have to purchase it from a vendor, hopefully the original manufacturer, there's a element of risk of third party vendor having physical access to the device, and therefore altering the hardware wallet, with a wallet that you download, verify, and then keep in a offline environment you don't have these risks.
Hence, why I went on, and said about being more confident in securing a seed than a hardware wallet. Although, I could've probably been a little more clear in that. So, if I wanted to just generate a seed, and basically have a offline wallet, I'd probably not even need the offline wallet, copy the addresses, save the seed, and focus on securing that seed. Even, if you are going to be keeping the wallet offline, as long as its secure in the first place, it's no less secure than a hardware wallet technically. However, when regular access is needed, and therefore becomes a online wallet, a hardware wallet makes sense due to the reasons you mentioned.
However, for private key generation or a offline wallet, a hardware wallet is definitely more expensive, and potentially overkill if it's going to remain a offline wallet. If you intend to use it regularly, and therefore online then yeah I'd absolutely agree that software wallets then have more attack vectors.
It seems like the OP was talking about holding Bitcoin, hence the reason I believe a offline wallet should be fine, and technically could potentially have less chance of being compromised in a physical attack, since there's various ways of securing it, whereas a lot of people tend to think hardware wallets are invulnerable even physically, and buy them from third party vendors quite often.
The key thing is; if you want a offline wallet, that you are holding Bitcoin on; offline wallet generated via verified software. If you want to regularly use it, and therefore online; hardware wallet. The added risk to a hardware wallets depends on how you got it, and how you secure it. Those are the additional risks, with the latter also being true for offline generated wallets.
Worth noting, while the vulnerability was patched, I wouldn't doubt that we'll see similar attacks, but there's also less secure hardware wallets than a Trezor. Trezor are pretty decent hardware wallets compared to some out there.
So, my line of thought was due to third party vendor issues or an attacker gaining physical access it could potentially have more risks. Although, I'll admit I didn't really explain that all too well. However, the chances of someone doing that, and having a zero day exploit? Probably, rather slim. Although, worth mentioning since you can avoid the risk of that by not using it at all. What I will say; for the vast majority of users, a hardware wallet is probably going to be the most secure, especially for new users. Again, I should've probably mentioned that, but thought there was enough users saying that
.
theoretically probably wasn't the right word. Needed to be something like
if a offline wallet is generated under perfect circumstances, e.g airgap etc, then it technically can be more secure than a hardware wallet if it remains offline, or the seed is backed up, and then the wallet is deleted from the computer. I don't know, a lot of people will think physical tampering of a hardware wallet before it arrives to you, is so incredibly unlikely it probably shouldn't be worried about it too much, especially if it's bought from the official store. However, not everyone has that privilege since they don't always deliver worldwide. One thing for sure, is that is a risk that you don't have with a offline wallet that you generated. However, you still have to keep your seed secure, and obviously your hardware wallet due to physical attacks potentially being an attack vector.