If you take up painting (art, not houses) you should know you will never be Rembrandt and it should not keep you from painting (Unless painting houses is your hobby)
With things like (marathon) running, hiking, it is easy to meassure Objective progress and qutie hard to moneteize.
If you are a programmer all day, and your hobby is programming I dont think that is ideal.
I have been there myself a bit earier in life and regret that now.
Thers is soo much to see, experience, learn outside of computers.
Plus doing something else will help your brain relax, or at least not running the exact same parts as when you are at work, that is in itself a valuabe thing. Giving your brain something different to chew on, connect new paths, all good.