Also anecdotally, I'd say the only things that would make a clearly noticeable performance difference to a
layperson or casual computer user from the last few years would be:
1. If they previously had less than 4GB of memory and were often swapping
2. If they previously had a spinning HDD and moved to an SSD
3. If they previously had a really low end CPU like something outside the Core range, and moved to an i5 or better
Beyond that, all the other stuff is either a marginal performance gain or a convenience feature. The only other "must have" thing from the last few years that I wouldn't want to lose is a high res monitor, but that falls into the convenience category for me and not performance.
Power users like your family member got quantifiable benefit from performance upgrades over the years, but if they were already running decent hardware like a Macbook Pro, they didn't get any life altering upgrades. Taking 15 seconds to compile vs 30 is definitely faster, but you still have to sit and wait each time you push the button, so any habits that you learned from the 30 second pause will probably continue.