Boards are getting designed for a specific chip and you are extremely unlikely to change that - unless the original is no longer available. Re-engineering for a new chip can be a massive pain - even if the new one is pin-compatible. If you are delivering high-quality products, you are not going to switch.
With the exception of some trivial ones, western manufacturers don't really make pin-compatible chips. Creating a chip which is electronically identical is not easy at all - and don't forget you probably have to make it firmware-compatible as well. The end result is that you now have exactly the same product as your competitor, so you are now competing primarily on price and making it easier for your customers to leave you. Oh, and you open yourself up to lawsuits too. Creating unique products is way for those manufacturers.
On the other hand, eastern manufacturers are more than happy to create exact clones. A lot of shitty electronics don't really care too much about things like longevity, warranty, compatibility, or even regulations. Just make sure it functions well enough to make it out of the store. So a manufacturer like GigaDevice creates the GD32F103, which is pretty much a clone of the STM32F103 by STMicroelectronics - down to firmware compatibility. Won't get used in any product whose brand you recognize, but with the ongoing chip shortage they are definitely selling like hot cakes.
But implementing an instruction set is not easy, and ARM might actually try to do something about it if you do it without their permission. With RISC-V, you can just grab any random implementation! Perhaps even an open-source one? GigaDevice has already released their first RISC-V clone: the GD32VF103. Again a clone of the STM32F103, but you now need to recompile for a different ISA.
RISC-V isn't, fundamentally, about pin level compatibility between manufacturers. It's about the ISA and its design. It's closer to AMD/Intel both providing X86 and x64 chips. Software will (mostly, modulo proprietary extensions) run on both, but they are not physically interchangeable. A EE/CMPE (or, more likely, team of them) still has to design the actual physical chips, and that's not necessarily going to be given away so freely.
Boards are getting designed for a specific chip and you are extremely unlikely to change that - unless the original is no longer available. Re-engineering for a new chip can be a massive pain - even if the new one is pin-compatible. If you are delivering high-quality products, you are not going to switch.
With the exception of some trivial ones, western manufacturers don't really make pin-compatible chips. Creating a chip which is electronically identical is not easy at all - and don't forget you probably have to make it firmware-compatible as well. The end result is that you now have exactly the same product as your competitor, so you are now competing primarily on price and making it easier for your customers to leave you. Oh, and you open yourself up to lawsuits too. Creating unique products is way for those manufacturers.
On the other hand, eastern manufacturers are more than happy to create exact clones. A lot of shitty electronics don't really care too much about things like longevity, warranty, compatibility, or even regulations. Just make sure it functions well enough to make it out of the store. So a manufacturer like GigaDevice creates the GD32F103, which is pretty much a clone of the STM32F103 by STMicroelectronics - down to firmware compatibility. Won't get used in any product whose brand you recognize, but with the ongoing chip shortage they are definitely selling like hot cakes.
But implementing an instruction set is not easy, and ARM might actually try to do something about it if you do it without their permission. With RISC-V, you can just grab any random implementation! Perhaps even an open-source one? GigaDevice has already released their first RISC-V clone: the GD32VF103. Again a clone of the STM32F103, but you now need to recompile for a different ISA.