Interesting. I've done things the other way around. I've spent the past decade as a freelance journalist, so I made my career before discovering Medium. Then I saw an opportunity to repurpose some of my old articles on here... but as these things go, they flopped. So I learnt it's a very different market and I need to write different material. So now, I'm trying to make Medium part of my income. But it's not a stepping stone - it's a sideline. I've already done the better things. It's just hard out there!