If you are working within the .NET space you have the option of working with Xamarin for mobile, Unity for games, WinForms or desktop applications, WPF, the list goes on and on etc; not to mention the myriad of plugins, extensions and diverse array of libraries at your fingertips. If you navigate these complicated environments - kudos to you!
To be a "developer" means to find cost-effective solutions no matter the problem and to be as confident as you possibly can about the choice. Competency is key, but it can't possibly be everything. Implementation takes time and deliberation (not just prowess) to take effect. With .NET 5 on the horizon I hope we reach an era of new understanding and we can all aspire to achieve a focused understanding, for as long as we/I am able.