But SPARC and Solaris are basically dead, iOS isn't a general-purpose computing platform, and Android doesn't fare much better. Is there any way to actually get this on a useful desktop or work station?
This is not an accurate statement. Oracle is still actively developing Solaris 11.4 and releasing regular updates. They plan to support Solaris and SPARC systems to at least 2034. This does not sound very dead to me.
Intel has dropped MPX support from newer generations, given that their design was buggy and no one bothered to actually make use of it.
So they decided that improving the design wasn't worthwhile.