Before I caught the Super Cooties in late 2021, I typically did 90 rpm on flat terrain, and 100+ on hills. We don't have any mountains here and I can't recall ever encountering a continuous climb, without any rollers, lasting more than a few minutes. I doubt I could have sustained some of those 110+ rpm sessions for very long.
After the respiratory bug my aerobic capacity never fully recovered. My recent chest imaging shows some lung scarring. At the same time I was doing more running, which affected my cycling. My legs got stronger, but slower in terms of reflexes. And I'm just getting older.
So now I tend to mash more, averaging 75 rpm all around, often dropping to 40-50 rpm on climbs when I'm standing to stomp the pedals because I don't have the aerobic capacity to spin anymore. And we lose aerobic capacity and quick reflexes with age, quicker than we lose muscle strength. So for many of us it just makes sense to pedal harder gears at slower cadence.
I still do faster spinning sessions in intervals but can't sustain it like I did before the Super Cooties. But it's useful to mix up the training, same as I do when running.
I don't worry about the "spin to win" thing anymore, which was often taken out of context. It developed during the peak of the doping era when EPO and blood doping enabled turbocharged cadences that would have been impractical in other eras. Physiologically, sure, the respiratory system recovers more quickly than the leg muscles, so for a three week grand tour with lots of climbing, spinning was more efficient. If they could sustain it without gassing out. Which is where the EPO and blood doping came in. Steroids, such as testosterone patches, were for quicker recovery from intense muscle strain, not for bulking up or "strength" per se. Floyd Landis discussed these strategies in a long interview he did several years ago, which can be found online.