I didn't mean just x86 because Apple Silicon isn't x86. I'd say the Surface Pro X falls under the tablet category. I'm not saying Apple invented ARM or the big little concept but Apple was the first to make them work on mainstream devices. Before Apple Silicon, ARM was generally in devices that required low power like phones or tablets or cheap devices like low end Chromebooks.True, it's never been a thing on x86, - but it's something developed by ARM and - until you go back to ancient history & Acorn - ARM in desktops/laptops has never been a thing.
As has already been posted - the Surface Pro X which snuck out just before the M1 used the technique - you can argue the toss as to whether it sold enough to qualify as a "thing".
...but Apple Silicon grew out of phone/tablet technology where big.little (or similar) was definitely a thing.
Before everyone was happy with the status quo like if it works why change it. Now even Qualcomm is claiming to have something in the works that will compete with M1. I think this is the start of a new generation of processors. Maybe even ARM will be the new x86 for Windows computers. I don't mean the current Qualcomm ARM but fast ones like Apple Silicon.