Earlier quoted context omitted.
Why should knowledge or experience be charged ? Isn't it in the interest of the whole humanity to be able to charge only for materials ?
Why should you be entitled to the mental labor of others? What good is it to spend years studying and doing work in a field if one can’t charge more specifically for that knowledge and experience?
Your concerns are valid, yes, but only if you value money over self-accomplishment.
I learn skills for myself, not for others. It's about investing in yourself, the output is not necessarily money. You can learn dance classes, it'll never pay-off, but you'll feel more accomplished.
Furthermore, from my perspective, money is unfair and is not a reflection of social value.
Because not the most deserving people are earning the most (the farmer who feeds others, vs, someone sharing pictures on OnlyFans).
I often speak with people who are smarter than me, and they share their knowledge with me for free. One example is for machine learning. In return I do share my other discoveries in fields I know better.
In the short-term, it looks better to keep the knowledge secret. But in the long-run everybody benefits.
The others still have their knowledge, I have new knowledge, and together we can build something better.
I'm very grateful to people who share what they know without charging me every minute like if I'm on a phone sex-line.
And the best lessons are actually free (YCombinator, Bill Gates, Physics classes, etc).