> I calculated that, on average, I was spending 22 hours or more each week on social activities.
This is the premise the article builds upon, and IMO it's already a bit too much. I've done both: go out every night and don't go out for a noticeable enough period. Both are bad, both are draining. Even if going out means stepping outside your comfort zone, you should do it.
> 5 - You'll save a ton of money on drinks, restaurants, and travel.
Not all of these are equivalent in value and not all are that expensive. The expenses are usually negligible compared to other stuff mortgages, leases etc (depending on tastes, but usually holds for tech people).