the hard drive one is more the concept of measuring things in base 10 or base 2, its caused by the rounding of 1000(10^3) vs 1024(2^10), hence where theres a difference between Gibibytes and Gigabytes.
finfetts decision was basically, its physically supposed to be one number, but folding it offers a performance increase (but not exactly equal to doubling transistors) so be picked an arbitrary lower number to represent ts peeformance. the problem is because its arbitrary, TSMC/Samsung gets all the power to fudge the numbers up.
if intels 10nm was more dense than TSMC 7, it shouldnt have been called TSMC 7, it should have been closer to TSMC 10 or 11.
12/16nm is when finfett technology was used, and the start of where the numbers started to get fudged.