How many of these niches actually pay enough (or provide enough other benefits) to have a decent quality of life? I think that's the real limiting factor in "finding your niche".
That's a fair point. I kind of hate that the world has come to this. Everything needs to be justified through an economic lens. I wonder if life was easier in the past with regards to this.
Certainly not. These days, with the Internet, social assistance programs, ability to run i.e. a Patreon account to make money from your hobby... It might not be "easy", but it's certainly easier than in the past, where taking a break from your farm to paint some trees would mean a very hard year.
To some degree, "everyone in the village is a millet farmer" did make it easier in the past to fit into a niche: it's the ultimate detachment of "who you are" from "what you do". Your day job is never-ending, will never be fully done, and means nothing. Today, we have it a bit harder because we expect our job to give us meaning.