The best R5 SoC is about as fast as a Pi 4 and better in many ways but also much more expensive.

https://www.eswincomputing.com/en/bocupload/2024/06/19/17187920991529ene8q.pdf

R5 is improving faster than ARM. There are more companies designing R5 chips than ARM. The R5 software ecosystem is essentially ready and waiting.

For many workloads, the GPU or DSP is more important than the CPU. R5 is becoming viable for these use cases.

Automotive, automation, quality control, robotics, aI, are all within reach. The SBC market is just the mainstream version of that. And desktops are just further along the price / performance curve from there.