They do. Someone with a salary of €400,000 would take home approximately €242,000 after income tax.

Up to €10,777: 0% tax rate
From €10,778 to €27,478: 11% tax rate
From €27,479 to €78,570: 30% tax rate
From €78,571 to €168,994: 41% tax rate
More than €168,994: 45% tax rate

According to The EIU, the cost of living in Paris is similar to San Francisco.

If it’s something that people are using a lot then anything that improves the experience can be seen as increasingly important/valuable.

From a practicality perspective, they offer precision, feedback and speed advantages over membrane/rubber dome types which can be valuable in different use cases.

I haven’t used gamer brand mechanical keyboards in a while, but my previous impression was that they were overpriced and generally at the lower quality/poorer experience end of the spectrum. I think there are likely far better options out there at all price points.

For most users/use cases, there isn’t a need for for so many dedicated keys - if they are prepared to learn layouts with multiple layers. There are several notable advantages: cost, portability, reduced footprint (keeping hands closer together when using mouse and keyboard), and reduced finger travel/stretch. These last two are good preventative measures for carpal tunnel.

I chose a 40% ortholinear keyboard specifically because I make heavy use of the numpad in my work. I keep the numpad on one of four layers and I find using it to be quicker and more seamless to transition to than when using a full sized keyboard. I only wish that more manufacturers made ortholinear layouts…

Then grow your own. Your natural right of control over your own body doesn’t extend to the markets and industry of the society you live in.