I am of course aware of that.

But reducing loneliness is just a means to an end. My point is that there exist a lot of rewarding things that you can do alone at home, which may give you a hapiness malus because of the loneliness, but also a happiness bonus because you like the activity.

If a solution to reducing loneliness shall be sustainable, it better increases the happiness or rewardingness overall, too. Otherwise you see loneliness as a problem, but see the alternatives as being the worse options, i.e. by rational choice, the loneliness will not be reduced.