There's been a massive increase in high risk behaviors, an increase in road rage, and a spike in traffic fatalities since COVID.
If COVID brain damage affects motor vehicle operation, it wouldn't be so far fetched to say it negatively effects happiness and overall wellbeing. Covid causes a loss of grey matter affecting impulse control and emotional regulation.
If millions of people have brain damage affecting impulse control and we are all collectively quick to anger now, which will manifest as collective frustration and unhappiness.
Not unlike the theory of Lead poisoning causing crime in the 70s and 80s. Our generation may be suffering a similar fate as a result of COVID.