Viruses don't care about how many people are in a room, and this doesn't seem like something people are going to worry about much 10 years down the road.
At the same time, I'd much rather shop in a small neighborhood grocery store with 5-10 other patrons instead of 200. Trader Joe's and other retailers (at least in the bay area) have to delegate a full-time employee to the front door to throttle incoming patrons. This would free up that employee.
In my area Walmart has started making each aisle one way and counting people coming into the store. Just yesterday I went in and it's already devolved into no one following the directions on the aisle, no one seems to be in the slightest bit considerate about trying to give others space to go around. People were regularly reaching around someone getting an item and coming into close contact instead of waiting all of 5 seconds for them to get their item and move.
There are already plenty of news articles about customers doing increasingly outrageous things and attacking employees because they dared to tell the customer not to violate store policy around purchase limits, senior hours, mask policies, occupancy limits, etc. The fancy sign telling someone to wait will not free up employees because there will inevitably be a chunk of the population who ignores it outright and when they just walk in the door, others will follow. These policies are meaningless unless there's some actual enforcement.