I don't think x86/PC comparability is irrelevant. ARM is not an architecture. It's just a SoC where manufactures hook random crap to random pins and make patched to hell, non-upstreamable kernels:
Windows Mobile ARM at least required UEFI, but their bootloaders are locked. Most mobile phones don't support device tree. Even on ARM boards that support device tree, hardware support is still hit and miss:
My remark about it being irrelevant is due to the fact that for IoT applications, one doesn't care for backwards compatibility of existing applications.
IoT deployments are usually software developed for a special use case.
Then if the target platform is powerful enough to allow C, C++, Rust, Java, Lua, MicroPython, Pascal, Basic, <whatever language with rich library>, then the actual OS is also kind of irrelevant.
I am not thinking of boards to run GNU/Linux or Windows, mimicking a desktop experience.
Maybe it shows my 80's background, but for many use cases an Arduino like bare metal development is more than good enough, hence x86 being irrelevant when one has an high level language with a nice abstractions SDK.
If software compatibility across a broad range of devices becomes important, then the ARM ecosystem will just move to broader adoption of device trees. Switching architectures to x86 just to get a standardized platform doesn't make sense.
I'd love to have small, low power, easy to setup, x86 chips or modules-with-BIOS, in the 40-200 MHz range, with 486DX/DX4/early Pentiums instructions and similar or better performance; possibly with a few basic SoC functions (UARTs, simple VESA-like graphics (no unusable 3D acceleration), integrated memory). And not some Chinese NDA doc-less chips like Vortex.
Specially when talking about CPUs good enough for high level languages like ESP32 (hello PCW 1512).