If that's your interpretation then we fundamentally disagree.

"Random guy on Youtube" happened to be an intelligent and capable human being who learned all the relevant techniques and principles from available information without paying for "credentials".

Go watch the technique used for testing, evaluating, sorting, and re-using batteries used and tell me specifically what is unsafe rather than trying to spread fear because there's no college degree/certification/other form of economic gate keeping.

I'm not attacking people with credentials, only the type of people who vaguely threaten people not to twist 120VAC wires together in a wirenut unless they understand Maxwell's Equations.