https://phys.org/news/2018-10-anthropocene-chair-sedentary-age.html

If I was asked to make even a conservative estimate of the number of chairs in the world, I'd find it hard to go lower than 8-10 per person. Applying that logic, there could be more than 60 billion of them on the planet. Surely chairs should be one of the universal signals of the arrival of the Anthropocene? Just like the data required to justify the change in the name of our geological epoch, they are to be found on every continent.

As to why there are suddenly so many chairs, there is no single clear reason. It is a confluence of fashion, politics, changing work habits, and the lust for comfort. The last of these requires no explanation in a culture in which ease and comfort are among the strongest drivers of consumer decision-making.