I disagree. Arduino was new because of the scale of its distribution. I built robots with Basic STAMPs in the early 2000's so I know there were prototyping platforms before, but they never took off in the way that arduino did.

And the openness of Arduino was critical to starting my own company, when I built an Arduino compatible board with a fast processor and wireless radio.

One could argue computers weren't new - we had vacuum tubes for ages. But it was putting it all together in a certain way (and the associated maturity of certain tech) that led to a step change in what those things meant.

For me, arduino similarly created an explosion of hobbyists working with circuits for the first time, and I'm happy that people who know very little have something to work on. But I am sad that the openness has been falling by the wayside.