Funnily enough modern machines have ISA in form of LPC bus used for few of the common peripherals (TPM) that can be used in ISA-compatible mode, and you can get LPC to ISA adapters.

They do apparently have an spi bus inside the pcie standard. Don't know if it would be possible with that or not though.

not being pedantic, just rounding out the record, ISA's follow-on, EISA, had already been around a while and was already sunsetting 30 years ago because PCI had already been invented. VESA also was ending its brief flash of glory.