Probably useful hiking if you get lost or injured to get help. Possibly useful in aviation for an off airport emergency or crash landing.
I watched some of it, I confess. I don't necessarily doubt this particular video, I'm generally a person who is sceptical and pessimistic about everything.
That's a 30 year old car he's treating at three year intervals with a well thought out and inexpensive procedure that anybody can do. Rust never sleeps, lol. Prevention is worth a ton of cure. If you have a sweet ride that you want to keep lookin good, this is great info.