I think you can make a good bit of side money on medium but very tricky to grow to anything substantial.

Having multiple ways of making money on a blog is crucial if you want to take it full time. E.g. MPP, custom site with ads, affiliate marketing (the big one), sponsorships, etc.

Building a blog is also a great way to build an audience for future endeavors. E.g. I eventually plan on making a piece of software for investors (in design stages atm) so having this blog will provide a platform to share it with when the software is in release 😀