No, C# is the 5th most popular programming language. They are also very different programming languages. See TIOBE rating here: https://www.tiobe.com/tiobe-index/

C# is widely used. It's used

• to develop video games with Unity
• websites and back-end processes and with ASP.NET
• multitudinous desktop applications with Windows Form Applications
• and now WPF applications
• universal Windows applications that can be deployed on PC’s.

read more: https://csharp1.com/