I agree with @LuckFreeZone . Uncertainty drove the increase in apps due to the difficulty in ascertaining one’s chances in a test-optional scenario, in either direction - adding more apps because they don’t know if they’ll get into their other schools even by submitting scores in range, and adding more apps if they think they might have a chance without submitting scores. Reducing the role/weight of scores from the process really did make this the wild west. How does a kid with “good” grades decide where to apply, and then on top of that, the early round results - deferrals, denials, reported increases in apps - piled on the uncertainty, leading to a lot of random apps thrown in during RD. One can only assume that class of 2022 will have similar levels of uncertainty, having watched the wild 2021 season.
If the universities want to address this problem of app volume (which I doubt), more certainty in where a student might be admitted, where they fit academically, would go a long, long way toward reducing app numbers. Since the colleges can’t quite describe it themselves beyond getting good grades in rigorous courses, nothing will change unless test requirements are reinstated or some other objective metric (other tests) becomes involved.
Limited college visits prior to app deadlines is an anomaly that will be reduced for 2022, though most juniors may have missed their spring break visit opportunities. At least visits should be back to normal for class of 2023.