Is it worth retraining from a .NET specialist to a mobile application developer?

Question

Android

Good day!
I work as a junior C# developer. I am writing various utilities for the desktop, now I am developing a web service (ASP.NET).
In the future, having gained experience, I want to try my hand at freelancing (UpWork, etc.). The question is whether it is worth doing development for mobile platforms in the evenings in your free time in order to enter freelance in this particular niche, since there is much more work for mobile phones. Or is it still not worth wasting and I will find enough work in my niche too, provided that I am a competent specialist?
Thanks everyone for the advice and discussion.

Answer 1

costs

Answer 2

Provided if a competent specialist, and if not?

Answer 3

Learn not only C# but also Python/Php/Ruby. The scope of work will immediately increase.
As for mobile phones, yes - it's worth it.