Mitigation measures aren't just based on science. They have to be both effective and reasonable, and what is considered reasonable depends on factors that are often social, business-related or political (in the general sense) in nature.
Businesses like airlines and restaurants do what they are able within the confines of their particular business needs. The reasonableness of a measure is judged in light of the amount of good it actually does. People on planes need to sit close together; at one point, the airlines were blocking middle seats, but the amount of good that was doing in such close quarters led that practice to be abandoned. Table service restaurants by their nature will have people indoors for a significant length of time without wearing masks. People seem to be okay with wearing masks entering and leaving, but the idea of asking them to put on masks between bites was rejected because it would not provide enough added protection to justify the downsides of the practice (fewer customers).
People differ immensely in balancing reasonableness with effectiveness, which is what we're seeing in many of these arguments. When people had no way to protect themselves from the virus, they were willing to accept a high level of restrictions as reasonable. This is going to change as more people are vaccinated. People are going to look more critically at restrictions, asking not whether they do anything at all, but how much they are actually helping.