In the piano-/synth-keyboard world, this is accomplished by 'interlocked blades', consisting of two curved blades interconnected with notches for each key, allowing the curve of the pressure mechanism to be tuned according to the depth and scale of the notches.

Its always curious to me that this technology hasn't been adopted in the QWERTY keyboard field, although that may be due to patents .. as I understand it the piano keyboard manufacturers are very aggressive about protecting these patents, and its one of the reasons that all synth manufacturers get their keybed mechanisms from the same supplier (Fatar TP9S) .. though recent technology has moved on to use piezo-electric switches.

https://www.fatar.com/products/tp9s/

(Some other interesting details here: https://www.fatar.com/products/)

There do exist switches with an almost flat force-curve, but those I've seen have been very light. For example 30g Topre.

The foam has disappeared, but the enthusiasts are going on. While it's not a craze, I believe mechanical keyboard is still superior for longer writing sessions (Apple's and Logitech's scissor switch keyboards are pretty good, too).

Gamers are moving to hall effect switches because of the things they enable, but from what I have seen, some people are still building their keyboards, and people still use mechanical keyboards.

I'd love to continue use mine, too, but they are bit too noisy for my office, and I don't continue computers at home as much, anymore.

Another chilling effect is caused by the tariffs, because people can't get their keyboards or parts as easily anymore. I got mine from Kickstarter directly, but it's impossible for me now.

They have become mainstream, so they are not special any more.

Even keyboards with what used to be enthusiast features, such as aluminium case, double-shot PBT keycaps, switch foam, plate foam, flex cuts, hot-swap, damping, etc. are available off-the-shelf at very reasonable prices now.

Various patents expired and now you can get excellent typing keyboards from China for $30-50. Basically everyone I know who types for a living has one.

Gamers have moved on to analog keyboards which are controversial because some of their features straddle the line into cheats. e.g. with an analog keyboards you can negate all inertia in Counter-Strike or do speed tricks in Trackmania not otherwise easily accessible to keyboard players.

Mechanical keyboard is still a sensible choice. With the advent of cheap 3D printing and custom PCBs, there's now also a lively DIY community, especially for odd/split layouts. I don't think it's a craze. It's just a hobby.

It's still a craze but the people who want a nice keyboard to use daily found theirs and drifted away from the novelty/modding, I think.

I've used a HHKB Pro 2 since 2010 and it's still going strong. I have a replacement ready if/when it dies, but other than a shiny space bar it looks and feels like new.