Has your son or daughter said he or she is lonely? If not, that's a big, big assumption.
I'm taking some liberty, but a recent email from a parent serves as a good illustration, too. I am reworking this slightly:
"Trying to imagine my son's thoughts, I tear myself to pieces over what must be going on in there. I worry that he might be experiencing great emotional pain. I keep asking him, and he assures me he is not."
There you have it. Trust the autistic or the introvert (or both) if he or she is content being alone. You can be alone, and not lonely.
The problem for parents it that most people do define success and happiness via relationships (and a job). My best relationships are with my wife, my sister, and my mother. I suppose those women do have a choice in the matter, but so far they tolerate me better than any other people could. I do not have a wide group of friends, and only a few acquaintances. But, I do love my wife and family. I'm content with those good relationships instead of a dozen less meaningful connections.
Now, the job issue is quite real and serious in any society. It might not be about money, but in any community members aspire to a valued role. Not everyone aspires to being a social leader, granted. What we want is to know our daily work is appreciated. Money is only one way to recognize value, so don't base your self-worth on dollars or euros or yen.
Yet, I've met autistics quite content to think nothing of if they have social value. I admit, I write and want an audience. Maybe the readers, viewers, or listeners to my words won't know my name, but there will be a value associated with what I create. That means something to me, too. Having an audience gives my work value, whether they see a play for free or pay several dollars for a book. It would be crushing if people walked out of a play during the first few minutes or never finished reading my columns and blogs.
The problem with wanting my work to have value is that workplaces require social skills and social connections. I've written several times that my poor social skills have led to problems in the workplace. I have no great answer for overcoming that challenge. It isn't that I want to have friends at work, but not having those friends can be a problem.
I am not charming, not socially engaging, and generally do not care about my coworkers. That doesn't mean I lack all empathy, but at work I need to focus on… work. That's a problem, and I don't have a solution.
In the end, this goes back to not assuming that "autistic" perceptions and desires are universals. Parents talk about "friends" at work because they assume friends help in the workplace. I'm sure I could unravel all the reasons if I thought about this, but I really find maintaining friendships at work exhausting. Trying to maintain social connections and work might be more than I can do.
If your autistic child says he or she doesn't want friends at work, or doesn't have any, that might not be a "problem" to the autistic person. Yet, I do know not having friends at work means you don't have defenders or mentors. Why should I need alliances at work? Because adult life is like junior high, sadly.
We constantly hear and read that autistics have trouble imagining what others feel and experience. It turns out, others cannot imagine our perspectives. Ironic, I suppose.