All from an engine cc of about half that of the Jag (maybe fractionally more).
Well, engine technology has improved somewhat, but a big part of that is because the Jag 4.2 probably weighs significantly more than the Ford and while it
looks like a sleek, prancing cat it actually has the aerodynamic efficiency of a brick. Even in the 1980s a lighter car with a smaller engine would have beaten the Jag. So it comes down to what you want to achieve - if you
want to drive around in 2 tonnes of steel and walnut burr in 2022 while winning drag races with Ford Focuses you're still going to need a much bigger cc engine.
Likewise, the efficiency of Apple Silicon
may have enabled you to get away with 8GB less RAM for general workloads, but if you had any justification for buying
64GB of RAM in 2018 it was because you needed to hold many gigabytes of data (bitmaps, audio samples, big data whatever...) in RAM without swapping and there's no reason for that data to have gotten any smaller in the intervening 4 years.
Yes, Apple Silicon is more efficient at swapping than Intel, but SSD is still an order of magnitude slower than RAM - plus excessive swapping may wear the SSD - so if you're relying on swap to compensate for insufficient RAM you are still getting sub-optimal performance out of your processor and GPU.
...a lot of the initial "8GB on M1 is 16GB on Intel" youtube raves seemed to come from people comparing 8GB M1s with 16GB Intel Macs who never bothered to check whether their test was actually
benefitting from the extra RAM on Intel (which means looking at memory
pressure and swap rates, not the 'memory used' figure) in the first place.