Back in the day when men were men 10-speed meant 2 on the front and 5 on the back we had to make use of every combination so we did a lot of that kind of stuff. Some guys would, indeed figure out the optimum gear progression and tape it to their handlebars.

As the number of rear cogs has gradually progressed, we have many, many more ratios to choose from. So many that most riders don't use them all. I think of a 3 X 10 drive train as having 3 gear ranges: 1 for steep uphills, one for use most of the time and 1 reserved for downhills and tail wind days. The rear derailleur serves as a trim within those 3 ranges.

I have neither experience nor interest with electronic shifting, but I can see where that may actually bring back the old days. Electronic shifting can "remember" all of the potential ratios to pick the next one in sequence and shift both derailleurs to optimize the chain line.