Everyone does not need a printer. A creative professional like an architect, engineer, electrician, decorator, wood worker, they absolutely need it.

Mass marketed are always cheaper and most of the time better. True.

So why creative professionals need it? Because not everything they need its mass marketted. In fact, one of the best uses is joining two mass marketted things together to create a system.

3d printing is fantastic for joining the gaps that exist between what exist in the market and exactly what you need.

Imagine you are an engineer creating a flight simulator hardware machine, or a driving simulator with VR. You probably will buy the chair, but then you will have to adapt it some way to your structure of soldered beams.

You can spend like 600 euros mechanizing and soldering little metal pieces and wait something like a month for those that make it to make it. Or you could print them and spend like 25 euros and have it ready at the end of the day, look at the problems in the design, iterate.