I see several people saying they are using air-gapped computer system instead of hardware wallet, but I think this is not the best option for most people.
It is easy to make mistakes with offline computer, with operating system, connection with other devices, and with many other things.
Another negative side is that you cant exactly easily make this system portable and usable in the same time.
I am not telling everyone to buy hardware wallets, but there are plenty of small portable DIY devices (raspberry pi zero, maix amigo, M5StickV, etc) that are much than laptops.