Joseph
“Someone remind me the logic of why supermarkets and parks (both sometimes packed as evidenced by recent photos) are okay to remain open but shuls are not.”
In addition to the reason already mentioned.
When shopping you (should) get in get your food and get out. The idea is not to sit there for a while next to other people. The odds of catching something from the brief moment passing another shopper is minimal (though not zero)
If thats how you daven in shul, well you are doing it wrong.