Kindly explain. Thanks.
If you understand my method, you would realize my method is very closely similar to having a hardware wallet. In fact, my method is also very closely similar to a paper wallet. The only difference is it is in digital format and fully controlled by the user. Paper wallet is not digital. Hardware wallet is not fully controlled by the user. In fact, I derived my method from https://en.bitcoin.it/wiki/How_to_set_up_a_secure_offline_savings_wallet, but simplified.
My method does not need different OS like Ubuntu. It also doesn't depend on 3rd-party hardware wallet. And yet it achieves similar, if not higher, level of security, as well as much higher control.
Thank you. Let me scrutinize it a bit to the benefit of all. So that we can make informed decisions.
1. "Hardware wallet is not fully controlled by the user" - A hardware wallet such as Trezor is issued by a 3rd party, but not 3rd party dependent in terms of recovery (https://news.bitcoin.com/trezor-moves-closed-source-backend-server-open-source-using-bitcore/ + https://doc.satoshilabs.com/trezor-faq/threats.html). Even the "clean air-gapped computer" you use was manufactured and provided by a 3rd party (as well as the software).
2. What do you use as a "clean air-gapped computer"? How big is it and how much does it cost?
3. "And yet it achieves similar, if not higher, level of security, as well as much higher control" - How come? "Used correctly, an air-gapped wallet is safe from all online threats, such as viruses and hackers. It is however still exposed to offline threats, such as hardware keyloggers, extortion, or people looking over your shoulder" (https://en.bitcoin.it/wiki/How_to_set_up_a_secure_offline_savings_wallet). This while Trezor eliminates more than one of these risks, including the threat posed by hardware keyloggers.
4. "Sign up for a few different cloud drive accounts such as Dropbox or Google drive" - How are "cloud drive accounts" cheaper and safer than what Trezor provides?
5. "Download Bitcoin-Core Linux binary and save it on a USB drive" - The Bitcoin-Core Linux binary is over 145 GB large. Many parts of the world don't have access to cheap internet access and bandwidth. How do the cost of downloading 145 GB+ (and growing!) plus the cost of an USB device work out cheaper than 89?
6. "Shut down your computer, and boot Ubuntu (or Linux distribution of you choice) from a liveCD" - In other words, you make use of software provided by a 3rd party? How is this better and more secure than what Trezor offers?
7. "Backup encrypted wallet.dat file in several places:
Send it to your 5 best friends by email attachment and ask them to save it for you.
Save it on your cloud drive accounts created in step 1.
Save it on several USB drives and CDs and store them in different geographic locations"
How is this not exposed to lost and/or theft as you claim?
I could continue, but the above should suffice for now. Thanks.