Let's talk about the king solution of keeping your Bitcoin safe, which to me is the airgapped hardware wallets but is it safe to say that they are 100% safe? I think the answer is no..
According to the majority, hardware wallets are the safest place to keep your assets, as well as air-gapped wallets. Since you are exchanging data in the computer even if you didn't use internet connection there's still a risk.
3. QR Codes: honesty, QR codes are not readable by the eye, they comes with blocks like figures, there is no way to know what's written in that QR code anyway, there is no way to read it and know what kind of data is inside it.
We can't read the QR Codes by the eye but it can easily be converted to text, so we have to avoid exposing our QR Codes anywhere in social medias.