Totally. But today, the room will not be well set up for it, markers may be dry, whiteboard covered in old, settled in diagrams, etc. All solvsble, but not in 30 min.
And for larger work presentations the expectation even 30 years ago was not whiteboards; that is very inefficient. It was transparencies. But try printing those in a pinch. And finding a projector.
When I was still teaching, I’d do this sometimes. Just do a lecture with a whiteboard and draw data structures and algorithms. It’s often much more engaging than prepared slides.
Yes, I know it doesn’t work for every possible presentation, but for many it does.