Hello, I have the feeling that buttons will be dead within the following decade (thumbs up if you read this on 2022). If buttons are used then it will be for very specific purposes or strictly defined amount of usability/interactivity. In that spirit, I get the feeling that nodes will be the future in many occasions and will replace traditional concepts of buttons and menus where required. If not, then a hybrid concept (GUI/Node just like Cycles) will be very popular, but in the core it will be all about Nodes.
With Nodes, it’s like creating entire systems (node setups) inside a system (a sandbox), when you need tremendous amount of agility/usability/freedom/experimentation then you definitely need nodes. In other terms, you get expanded creativity possibilities.
Some use case examples:
Blender Cycles (Materials, Textures)
Well known to everybody
Blender Post Processing (Well known concept in the movie industry used in many suites)
Blender Particles Nodes (and generally physical simulation)
UDK Animation (Animation based on interactivity)
Houdini (Procedural Modeling)
You get the idea right? Last but not least, there is Node based programming environments. (There was a conversation about fitting one in Blender)
So definitely things have changed, Nodes will be very useful.