Java Vs C#

C# is extremely popular in the gaming business. Anyway, if you master one object-oriented programming language you can easily switch to another.

Off the top of my head Powershell and Xamarin. Then add the Microsoft maintained open source libraries that extend the functionality of everything from Visual Studio to the Xbox.

For this to be true you are implying Google refused to develop a Youtube app because of the choice of programming language. You are talking out of your backside.

Microsoft refused to give APIs for Windows mobile.

Which gaming? Unity?
In gaming c++ rules

Unity uses C# and JS.

For web based programming, I would recommend Python /Javascript instead.