> Arduino got obsoleted by the Raspberry Pi and its clones/compatible devices.

Not entirely. Arduino was always targeted at the "casual DIY" segment - artists, school robotics clubs, and other folks who wanted automation without a steep learning curve. This was a notch below the "serious hobbyist" tier where you could save a lot of money by just buying a bare-metal version of the same chip and write some code in C (or Rust). Or the pro tier, where there's way you're paying $20+ for a glorified breakout board.

Casual DIY always had a ton of inertia. It's also the reason why every other design for an analog guitar pedal or whatever is using components that are 50 years old: ancient designs are just copied-and-pasted forever. So I don't think Arduino is dead there, although other platforms are definitely eating some of their lunch.