My own observations have been that my coworkers, highly educated, very vocal about pro vaccination stance 2020-2024, really good about isolating after international travel just in case or when even slightly I'll.

Suddenly late last year seem to have taken a shift to making statements like "I get sick more now since I've been getting COVID boosters, so I'm going to stop"

"When I do get sick it's not that bad so not going to bother with boosters"

I love a good conspiracy theory, but it kinda feels like the appetite for risk suddenly increased for a bunch of people over a relatively short period of time, as well as suddenly believing getting sick is safer than vaccinating, not for all vaccines though just the COVID one.