Password Entropy = length * log2(possible_chars). So this would actually add 7*log2(10) => 23 bits of entropy, assuming the attacker knew that this section was numeric, or ~45 bits if they didn't.

For anyone curious: Current best practice is a minimum of 100 bits, or 16 characters assuming only letters, numbers, and special characters. The recommended minimum bits increases every year with computing power.

(yeah yeah but that's not funny so I ignored it :p)

Look up how hard it is for humans to remember long strings of numbers. That is WHY ICQ (and eventually phone numbers) were dropped almost immediately in favor of social media and the ability to exchange numbers just by tapping phones.

And in the time it would take to memorize a bar code (12-ish digits, depending on standard) you likely should be rotating that password anyway. And in the time it would take to memorize it you are also very blatantly reading off a sticky note as you "discretely" look at your notebook every time you want to access your password database in public. And if you aren't in public? Why go through these extra steps when there are much better ways to secure this that are a lot more obvious if they are tampered with.

I get that a youtuber you like talked about this. Youtubers talk about a lot of stupid products in the interest of making Content. But maybe listen to the people who have experience with this kind of hardware and the kind of security theatre policies that make them "a good idea".