Costco seems to be enforcing it easily enough. I guess people are used to having to be checked going in for card. I've been several times and seen 100% mask compliance.
Kroger near me just put up a sign saying masks required this weekend. And publix put up a sign that said "Thank you for wearing a mask" but it seemed to stop short of requiring it. In any event, I went to both stores this weekend and saw only one person unmasked. That's the highest percentage I've seen. It's been running about 60-80% depending on a given visit, but near 100% at both stores combined this weekend.
That being said, I had to take my vehicle to the dealership for service last Friday. The service office is about 10' by 15', with a round reception desk type of setup, with 6-7 or so "service consultants" in their seats about a foot apart from each other. Then, there are the customers, up to 5-6 at any given time I was there.
None of the service people were masked, and all but one were clearly over 55. They're sitting in their all day for 8+ hours, with customers coming in and out, and all the technicians running in and out, and you'd think there was nothing up other than every customer I saw was masked. And these guys, in the most vulnerable age, just didn't care.
It was pretty disturbing. You'd think at the very least the dealer would mandate some distancing/masks, because if one person got COVID it would basically wipe out the entire service operation and revenue.