XMOS xCORE is actually a pretty interesting architecture that packs a lot of power.
It is just that there range of applications is a bit niche, they are too big, complex and power hungry to be a MCU replacement while they don't quite have the throughput of FPGAs. They tend to shine the most when you need weird interfaces at moderate data rates. This could be a fitting use for it.
I think that is a little harsh; they are much more than "weird interfaces"
They certainly aren't FPGAs and won't replace them, but they are a half-way house between conventional MCUs and FPGAs. They have the advantages of both, within their fundamental constraints.
I sure as hell hope they won't be the final answer to hard realtime and parallel computation - we need better. But they sure as hell are a good way of making people realise the limitations of conventional MCUs and languages.
But you can also get around the cache timing issues on modern MCUs. Most of them are ARM and it can execute code from anywhere, so you can just put a ISR into RAM closest to the CPU and that one typically runs at the same clock speed as the CPU so there is no latency variability. But yeah not when you have to watch for multiple pulses, timer peripherals are there for a reason.
That can be part of the solution, but with limitations.
There is no way in hell that an off-the-shelf toolchain can accurately
predict that multiple i/o operations and processing are
guaranteed to complete on time. You might be able to
infer part of those guarantees from the design architecture and implementation, but such inferences will require a lot of manual intervention and faith you haven't missed something.
Notable points about the xCORE ecosystem is the extremely competent way in which the hardware supports parallel operation and timing guarantees, the language
concepts support parallel computation, and the language
details support timely interaction with hardware. In comparison, C on conventional MCUs is stone-age technology!
As someone that has long been frustrated by the needless, false and damaging division between "hardware" and "software", the xCORE hardware/software/toolchain ecosystem beautifully blurs the distinctions - and shows what is possible.