Nothing if you feel it to be fulfilling but for a lot of people it raises the bar on what could be a fun hobby to something else and often includes a bunch of elements you'd normally not care about.

As a gamedev my brain is continually broken trying to make games in my own time because I'm so used to treating games as a product. There's a wide gulf between doing that as a hobby and doing it as a job. Particularly in motivation around the end result.