I note neither your post or the one you replied to contain any quantitative data about how many profitable solo businesses there are.
This is such a middlebrow dismissal. Like yeah, people are speculating based personal experience and knowledge, so what? If you have a different viewpoint or something specific you'd like to see data on call it out and engage in the discussion. Don't just be the "data or GTFO" guy because that's a super bland and pointless take.
I know over a dozen 1-2 person SaaS, not including my own. Some of them have hired some help now but they are still more on the "lifestyle business" side. They are in many different spaces, and founders from around the world. I am not a big networker, but this is my niche and it's big enough that I just know a slice.