The whole reason ARM transition worked is that you had millions of developers with MacBooks who because of Rosetta were able to seamlessly run both x86 and ARM code at the same time.
This meant that you had (a) strong demand for ARM apps/libraries, (b) large pool of testers, (c) developers able to port their code without needing additional hardware, (d) developers able to seamlessly test their x86/ARM code side by side.
Apple is the only company that has managed a single CPU transition successfully. That they actually did it three times is incredible.
I think people are blind to the amount of pre-emptive work a transition like that requires. Sure, Linux and FreeBSD support a bunch of architectures, but are they really all free of bugs due to the architecture? You can't convince me that choosing an esoteric, lightly used arch like Big Endian PowerPC won't come with bugs related to that you'll have to deal with. And then you need to figure out who's responsible for the code, and whether or not they have the hardware to test it on.
It happened to me; small project I put on my ARM-based AWS server, and it was not working even though it was compiled for the architecture.
This meant that you had (a) strong demand for ARM apps/libraries, (b) large pool of testers, (c) developers able to port their code without needing additional hardware, (d) developers able to seamlessly test their x86/ARM code side by side.
RISC-V will have none of this.