When it comes to sensors and latency, you can use a 200mhz cortex m3 with a bespoke runtime you write in a couple weeks, or you can throw a real OS on top of multiple Ghz and cores in order to make up for the overhead of having a real OS.

SRAM running at 200mhz with 1 cycle latency can perform what looks like miracles when placed side by side with DRAM running at LOLWTF Ghz that is stuck behind 100 cycles of delay talking to the CPU that first tries to work its way through multiple steps of onboard cache and lookup buffers and all sorts of fun things.

Embedded controls can do stupid amazing things with very little resources because all of a sudden you have removed a huge constant delay from all memory accesses.

Throughput, however, they don't do so well on throughput. :-D