The video on YouTube by that suicidal guy has been deleted. It is not healthy to pin one's feeling of agency on someone else's validation by making it your purpose.There is a feeling of powerlessness that comes with realizing that other people's validation isn't objective. Therefore making one's purpose other people's validation is better than having no purpose at all.
A lot of men seek other men's validation by gaining women's validation.
To abandon all that and live directly by one's own validation is not an easy thing to do - more so today because a lot of manual labour has become redundant. Sure you could still become a carpenter or something but it would still feel like a hobby, like some 'do-it-yourself' thing when Ikea can produce thousands of tables and chairs when you can only make one. It would be like a London banker going to work in his office dressed in Armour and insisting in talking exclusively in ancient latin. It would be larping. That is why a lot of survivalist stuff can't be taken seriously - because it is not necessary.
The only place where we can by and large appreciate what is unnecessary is art. Anyway you are correct it would be unwise to tell him to look into himself to keep going forward when there is nothing in himself that tells him to keep going forward. If he finds some woman he could at least live for her sake and perhaps when his wishes part ways with hers and he has to make compromises he might realize what his own wishes are.