Python Addins are a pretty great way to quickly extend ArcMap, ArcCatalog and the other legacy ArcGIS Desktop applications. However, if you want to develop addins for ArcGIS Professional, your only option is .NET. What a travesty! Esri is pushing Python so hard on users as the out-of-the-box API for extending ArcGIS that has almost no dependencies yet we don't get that in Pro? Meanwhile, Esri continues to move the Python API along, including the Anacondas distro, supporting Python Notebooks and adding all sorts of wild functionality. Yet, we leave Python Addins out in the cold?
We need a framework for developing Python Addins in Pro. Most of the hard work is already done. We basically just need bindings from Python to the .NET SDK. It's no small ask, I realize but it's well worth the effort!