First of all, everybody is different. Also, as pointed out above, the data mighr simply be confirming a trained condition.

But it's easy enough to apply the theory and see how it turns out for you. On any stretch long enough, try maintaining the same speed using either of two adjacent gears, ie one feeling a bit low, and one a bit high and see how you feel. If you have a heart monitor, see which allows you to maintain that speed with a lower heart rate.

For my part, I let my legs tell me and ride my natural cadence, which has increased over the years, but is still at the lower end of the range people talk about. Also, possibly because I didn't have them available when I was younger, I still can't spin up long climbs in a super low gear, and prefer pushing a higher gear using strength vs. speed.

IMO - unless you're training for competition, or have another training goal, ie. improving climbing ability, listen to your legs and ride however feels best, regardless of anything you read or hear.

FWIW - I used to ride with someone with breathing issues because of which he couldn't spin low gears. He set his bike up with monster high gearing, and could produce and sustain serious power mashing big gears. In his case, it was very clear that he could get more work on less air at lower cadence.