If you know how to use git, you will know how to use docker (provided you know what you want to do). They are completely different programs, yet you can quickly grasp the other instinctively.
Now, Photoshop and Blender - they are also different programs, but if you know Photoshop, you still need to relearn Blender’s interface completely.
This is why I prefer terminal programs in general. Unless it’s more convenient to use GUi, i.e. Drag&Drop file manager, some git tools etc.
It’s like you said projectors would replace TVs. But projectors are closer to TV than VR is to a monitor, they are more mature and much closer in price to TVs, yet most people own TV, and projectors are not common.
VR is a niche and always will be. It’s not more universal nor more practical than screen, and nothing will change that.