Yeah, with age most of us lose aerobic capacity quicker than muscle strength -- and we lose both pretty quickly.
I used to spin 90 rpm like clockwork, no particular effort. Over time that got more difficult. I'd gas out before my legs quit.
Last year about this time an old neck injury flared up so I was off the bike more than on it. I didn't want to lose fitness so I resumed jogging for the first time in almost 40 years. My legs got stronger. The knee, hip and lower back pain I used to experience trying to mash big gears cleared up. I switched to lower cadence, around 70-75 rpm average, often 60 on seated climbs and 40-50 when standing. No knee problems. I don't gas out so easily now.
I still switch between high and low cadence drills but my "spin to win" days are long gone. Anyway, that whole concept developed around the use of PEDs, especially EPO and blood doping, which enabled users to recover quicker from maximum aerobic capacity than their legs could recover from stomping big gears. Some dopers who've described the whole program said steroids helped with muscle recovery and quick reduction of inflammation. But blood doping to boost their aerobic capacity to spin faster cadence was the real key.
I don't have access to any of that stuff so the whole spin to win thing was always lacking context -- which we didn't know, or refused to acknowledge before widespread doping became irrefutable.
And more recent studies have confirmed that faster cadences have limited use to a relative handful of elite athletes.
Check Strava for data shared by pros -- some do, at least for training. Very, very few are spinning fast cadences consistently. Any spinning of 90-100+ rpm is limited to relatively short duration climbs ("short duration" for them might be up to 20-30 minutes -- more like 5 minutes for me). Most are averaging 75 rpm overall.
It appears few of them could sustain consistently high cadence without doping.