I agree that the most important factor here is not whether the person in question is able to work a traditional job and contribute to the economy. The way I see it, treatment and quality of life is what's important here.
Rather, I meant that he would likely be better off the closer to reality he got (i.e. the less his delusions impacted him), and that the delusional should not be patronized by allowing them their "eccentricities" and to remain in their own bubble (which now seems a moot point).
Like a lot people, I do ponder the quality of reality, and I also find it interesting that I will never know reality as you or any other person actually perceives or experiences it. I can only know that there are "overlapping points of agreement", based on our senses, mental processing, communication, etc.
But, there is certainly an agreed-upon reality on which our society is built.
Are there other ways for them to "participate in reality" other than by getting a job and contributing to the economy?
Look at the insanity in how we allocate resources and which activities we incent. People literally die as a result of our priorities.
So, should we assume that he is better off by "joining us" and contributing to that reality? I don't know. But, I don't think it's a foregone conclusion and it seems at least as important to examine that reality first.