> People need to purposefully and intentionally do things. Sitting home on an app, watching TV is easy. There is no fear or rejection, there is no work to get out of the house, there is no risk. But there is also no reward.

This is the wrong model:

Sitting (alone) at home and working on program code or reading scientific textbooks does have a reward. Many things for which you go outside of the house or where you interact with other people have a much lower reward. So you rather loose a rather decent local optimum, and if you don't know very well where to look outside for something really good, you get much worse results than if you simply stayed at home and do there what you love.

I think by "reward" in the context of this discussion on loneliness, OP may have meant the opportunity to meet people, make friends, perhaps hit it off with someone and land a date, if you're single. Not that it's entirely useless/detrimental to spend time at home reading or pursuing whatever solo hobbies you happen to have.

To be sure, there certainly are many introverts who are perfectly happy on their own with no need to get out and meet people. More power to them! But there are many that crave human connection, even if they happen to have many intellectual interests and for these types of individuals, they would be well served at least carving out some portion of their time to get out of the house with the explicit aim of meeting people. And yes, not every such outing will lead to lifelong friends or meeting your next soulmate, but it's a numbers game.

> you get much worse results than if you simply stayed at home and do there what you love.

That's a sense of risk and caution that gets too comfortable for some people to compete with over time. If you don't build yourself better options, all you want to do is sit at home and do the thing that guarantees a reward. Then you get in your car and move about the world in a way that you feel is guaranteed to protect you from conditions, other people, but really is dangerous. You bet only on certainty, and outcomes are predictable, but they're not compatible with not being lonely

It's also possible to write code or read scientific textbooks for the goal of promoting social connection.

My son is comparing every alternative to what he can accomplish by staying home and practicing guitar. However, we are trying to start an anime theme song cover band (e.g. "Upstate NY's most energetic opening act") for which he's going to play Bass, Rhythm or Lead as needed and I'm going to be the Kitsune/Band Manager/Mascot.

We are optimising for reducing loneliness, remember.

What a stupid take, but it showcases the underlying problem: there is no loneliness issue, there is a "me me me" issue.

Friendship is a two way contract: you add something to someone's life and they will consider you their friend, they add something to your life, making them your friend.

If you "optimize" for your own and only your own benefit, nobody is going to be your friend.