We live in a world where CAD and BIM applications generate extraordinarily large and complex files, which requires powerful file processing. An older plotter might manage to print such files, but it normally involves a long processing sequence to render the image. In addition, you will have greater difficulty finding replacement parts for an older machine. When a components break, you have to wait a longer length of time to replace it.
Upgrading also becomes advantageous because you will have access to the latest features. If you have been out of the market for a while, the technology has advanced. For example, you can purchase a plotter that consumes less energy to save money and access new features that lead to greater efficiency in the workplace. Deciding if you need a plotter boils down to checking the compliance of hardware and software assets to see if they are outdated.