My take is that this is the effect of the requirements of the companies producing hardware and is entirely unrelated to the CPU architecture. On desktop and ser

My take is that this is the effect of the requirements of the companies producing hardware and is entirely unrelated to the CPU architecture. On desktop and server consumers have a very strong demand that off-the-shelf OSes Just Work (so they can install stock RedHat or Windows) and so there is pressure on hw manufacturers to create and follow standards. Breaking away from the consensus standards is penalized, not rewarded. You can see this happening as Arm moved into the server space, too -- server Arm is much less heterogenous than embedded Arm. Conversely, in embedded devices there is little or no pressure to standardize, because often the system software will be a custom build for that device anyway, and end-users aren't expected to try to install a new OS on it. In this world, differences in hardware tend to be rewarded rather than penalized -- the funky nonstandard feature in your SoC may be what persuades the h/w designer to pick you rather than a competitor, implementing something in a weird way can shave a bit off power consumption or just save time in the design process, and so on. And because there's no requirement to have the end user install a new OS the temptation to save time in development by not trying to upstream kernel changes is often overwhelming. The difficulty with 'dev boards' like the RPi is that for economic reasons they're made with SoCs from the high-volume markets of the embedded world but sold to people who want to use them like the standardized hw of the server world. This mismatch tends to be annoying and inconvenient. Anyway, my take is that for RISC-V the dynamics will be exactly the same -- in the embedded world there will be a profusion of different hardware and a lot of binary blobs and non-upstreamed drivers; in the server world things will be nicer; and dev boards will be more like the embedded world than you would like. (Also, x86 is really unusual in having such a uniform every-machine-looks-the-same ecosystem; this has happened by historical accident as much as anything else. Of course most people only have experience with x86, but it might help to try to not think of absolute-x86-monoculture as 'normal' and wider-variety as 'weird', when it's the other way around :-))