Interesting. I've used C# heavily at my last couple of jobs and it has all been server side web work - mostly back ends of web apps, but also services and microservices of various kinds.

From talks with coworkers, the impression I've gotten is that most C# in the wild is running server side, though there's obviously a lot of it in desktop apps, and on mobile with Xamarin.

some legacy Windows server stuff - part of this could be rewritten to Linux/Go/whatever_server_lang just team mates are not willing to leave their comfortable VS env. if not provided with decent IDE/debugger

On our case desktop applications for interacting with healthcare and manufacturing devices, web sites and distributed computing.