One aspect of the 2020 COVID lockdown I found distressing was the complete shutdown of my usual spin classes.
Most of us regulars were on a first-name basis, but did not meet outside the gym: it sufficed to see each other at class. This casual sociability didn't return when the gym restarted the classes. The new attendees aren't as friendly with each other.
The 1991 film _Danzon_ has a poignant narrative about trying to find an acquaintance who has vanished.[1]