What will be (for amateurs) the real 1st killer application for home and/or professional

Hi @Alex_Fielder I was thinking that the software and mechanics of a Plotter must be very similar to 3D Printers. The only real difference is the medium they use for printing (i.e. plastic versus ink).
So while a tank and/or enclosure would be needed rather than a paper roll, the roll feed could be used to control the movement of the bed and the software/mechanics would control the position of the print head (which uses plastic, metal, glue or whatever).
I can’t help but to think a plotter would be an excellent start to a home-made 3D printer … but then I just don’t know !
One thing is sure, while many 3D printers are great for doing up to 10 inch x 10 inch x ? Tall 3D Models, this plotter print head travels 36 inches horizontally and the roll feeder travels up to 50 feet (by feeding the paper roll OR in this case, the print bed laterally).