Idea wise actually S/360 run on hardware microcode and all these idea of virtual machine and hypervisor came from an unauthorised development called CP67 or later VM. IBM used it for development MVS etc. as some hardware is yet to be built for certain features.

But the modern day these development is crazy.

How can yo manage a 100+ structure in a language you just learnt (Rust) for a secret GPU the vendor does not share info.