I think a lot of these small companies still mandating masks, queuing outside, bells for exempt people etc do so because they are still afraid of the council official with lanyard, hi-viz and clipboard to come around and tell them they are not #covidsafe. And for good reason, most councils don't have the clot to take on big chains, but John Smith the local butcher, well they can take out their frustrations out on his type all day long.
In terms of airlines, you have to remember that most carriers serve multiple countries, all of which will have different rules. And so they are simply going down the path of least resistance, so that they can tell the authorities of whichever nations they fly to that they are #covidsafe. But once in the air, if food and drink is available blind eyes are turned, especially with the carriers whose business models have a heavy dependence on in-flight sales.