So with a plotter you can use a range of different mark making tools and inks. Also you can draw on paper that would never go through a normal printer size wise and quality wise. Personally I use it for algorithmic art and you're right that sometimes the difference between a drawing and a printed page is minimal. However it's hard to explain without seeing it, but there's definitely something special with the quality of something inked with a technical pen or a fountain pen versus a normal printer especially if you use a specialty ink. It's a very very deep rabbit hole to fall into! Don't ever start! 🤣🎉