Compare with the web where LetsEncrypt just works without demanding a king's ransom.
As for the APIs, it is very easy to get into dependency hell between all the different UI technologies, .NET implementations, and target systems. Want to develop a brand new plain-old GUI app? Probably simple (although I've never tried, the web is right there). Need to develop a plugin for an existing application, or a new app for something like Hololens? Have fun.