This argument goes back 30 years. As far as I know, not a hardware engineer, it's not that much of an issue since the only complicated thing is the decoder, and

This argument goes back 30 years. As far as I know, not a hardware engineer, it's not that much of an issue since the only complicated thing is the decoder, and then it's microcode and not an issue. The TSO memory guarantee X86 is probably the exception, since Apple supports it on their M1s too for emulation.