"Hygiene theater",
the kind of symbolism that makes people feel like they are caring about their fellow humans, isn't going away, so get used to having someone unqualified stick a thermometer up to your forehead and we'll all pretend your grandmother will die if they don't.
The reason is the CDC, and then ridiculously hyperactive states like California, who still haven't even adopted the overly conservative stance of the CDC. Vaccinated or not, you have to wear a mask unless you are drinking coffee - and they weirdly tried to tell people to mask up between sips, the opposite of what every expert says.