I've mostly seen people highlighting the focus of hardware wallets and the hardened nature of them against more novel attacks.
Sure, they are hardened against side channel attacks, but they are also vulnerable to different attacks which airgapped, encrypted, cold storage is not vulnerable to. Seed phrases can be extracted from Trezor devices, and Ledger devices had a critical bug which would allow bitcoin to be stolen when the user was interacting with an altcoin, for example. Neither of these are possible against a well set up cold storage device.
There is no perfect solution for bitcoin storage, and each has its own pros and cons. But writing off cold storage because of incredibly difficult and rare attacks such as an attacker listening to the speed of your computer fan is incorrect, when by far and away the most likely way to lose your coins is through user mistake, simple malware (such as clipboard malware), or physical coercion.
$5 wrench attack is much more likely and that is why most HW wallets have plausible deniability built into it as well.
I would argue that the plausible deniability of cold storage can outperform that of a hardware wallet. With a cold storage device I can use hidden volumes to decrypt fake or misleading "sensitive" data much in the same way that a passphrase on a hardware wallet can lead to fake or misleading wallets, and in both cases I can keep my main sensitive data/wallet completely hidden. The difference is with a cold storage device I could be hiding anything, from bank details to business accounts to wikileaks data etc., whereas with a hardware wallet, it is immediately obvious that I am hiding cryptocurrency.
In terms of the theoretical exploitation surface, it could be argued that having a hardware wallet which is specifically designed for storing Bitcoins safely is better than a person with little to no knowledge having to set up one themselves and exposing it to unnecessary risks.
I would agree with this. A hardware wallet remains the logical choice for anyone who feels they do not have the technical knowledge to safely set up and use an airgapped device, but for those of us who do, an airgapped device can definitely be better than a hardware wallet, depending on what attack vectors you are most concerned about.