Much of the Revit developer documentation and SDK documentation is based on WinForms, a UI framework originally released in 2002, and superseded by WPF in 2006. As a new developer learning development through Revit add-in development, this can easily give the impression that WinForms are an appropriate avenue to begin developing with, despite a number of critical issues such as their inability to scale properly across mixed and high resolution monitors, and the fact that their general syntax and coding is somewhat archaic at this point compared to modern UI desktop frameworks like WPF, UWP, or web frameworks like React and Angular.
It would be ideal if the SDK examples would be updated to WPF, or at the very least if the getting started / My First Add In documentation explicitly guided you away from WinForms and towards WPF or made it clear what the drawbacks of developing with WinForms will be.