N64 has unique architecture that makes it very challenging to emulate even on hardware several orders of magnitude more powerful. I've struggled to run it on a full-size PC with a 7th gen i5 processor.
Emulating those platform is significantly more resource intensive since you need to emulate the entire architecture and interpret the assembly code, while more modern game consoles are running either ARM or x86/amd64 which makes emulating relatively simpler.