Things do not always get implemented in complexity order. A lot of the time it’s dictated by whether one has both a use-case and the means to implement it, and businesses have had money and a need to put things on paper for quite a while.
That being said, 3D printing is difficult and complicated, in software. Mechanically it’s quite simple. A DIY-er can easily copy complicated software to use a 3D printer, but you can’t easily copy complicated mechanical parts to make a 2D printer.
But we’ve had 2D printers for longer? That would imply that its a simpler task, not having to deal with temperature and layer adhesion and all.
Things do not always get implemented in complexity order. A lot of the time it’s dictated by whether one has both a use-case and the means to implement it, and businesses have had money and a need to put things on paper for quite a while.
That being said, 3D printing is difficult and complicated, in software. Mechanically it’s quite simple. A DIY-er can easily copy complicated software to use a 3D printer, but you can’t easily copy complicated mechanical parts to make a 2D printer.