My “plan” when this all started was to shop at 4 am. (24 hour store). Now the store closes overnight to deep clean and restock; I totally understand. I just need to come up with a new plan.
Thanks for the opinions, if during elder hours it is super crowded it sort of defeats the purpose.
I think it depends on the store and where you are located. I went on Wed to my local supermarket during senior/compromised immunity hour. I got there at 7:40, so I had about 20 min to shop before senior hour was over. So, I don't know what it was like right at the start of the hour and if it was a lot busier. It was wonderful.

There was only about 15 of us in the whole store, including the store employees on the floor. It was like we were playing human Pac Man.
We'd turn the corner to go down an aisle. If we'd see someone, we'd turn around and go down another aisle until that person was finished where we wanted to go. When I was at the sour cream trying to figure out which one had the lowest fat, I saw another person waiting till I was finished. So I grabbed one, walked away to check the label, so he could get the one, then I went back to look some more.
Today, I got to the same store an hour later. I just missed the senior hour. There were a few more people and I noticed they weren't so respectful of boundaries or waiting. And most were a few years younger. So, now I know to go earlier.
Although, the change in demographic today could be because the Whole Foods a few blocks away just closed due to an employee getting the Coronavirus. They've now moved to shopping the smaller, local store. I'm in NYC. I was in that Whole Foods 2 weeks ago, when this all started and we had the first few confirmed cases. It was a zoo. There was no such thing as social distancing. I just knew there was probably a couple people in that massive crowd that had the virus. And that was before we even heard that there are asymptomatic people. I wasn't going to take the chance of wading through that crowd. I swore I wouldn't go in there again until after this is over. I have a feeling it never stopped being that crowded. I'm not surprised an employee got sick.
I think the big box stores will always be busier. They naturally draw bigger crowds. The smaller, locally owned stores don't have as much traffic. I went into my local dollar store, not Dollar Tree, and again, it had very few people. I hit paydirt on canned goods there and plastic wrap. My suggestion to you is to try stores that naturally aren't as busy as
Walmart, Target, Whole Foods, Trader Joe's, etc.