That's under "professional growth". The idea that you advance in your career.
Things that advance your career don't always come with money upfront. Example: unpaid internships.
Unpaid internships are a lie told in industries who undervalue their hiring pool.
I disagree... Price is dictated by supply and demand. Industries are paying nothing for these interns because they can get away with it, not because they consider them worthless.
You pay nothing to breathe oxygen. How valuable is it to you?
When you need something done right, you pay for it.
When you do unpaid work, it means that it's work that doesn't matter, which means it isn't providing you with much in terms of valuable skills.