> Studies on the coronavirus circulating showed this at the very beginning of 2020.

This is only "obvious" with the benefit of hindsight. There was a mountain of rushed studies early on reporting all sorts of conflicting "facts" about covid. Of course using what we know now, you can look back and cherrypick a lot of great stuff from the pile of early results. But that doesn't mean you could have done the same thing in early 2020. How could you tell which studies to believe? Everything was rushed, had small sample sizes and nothing had been replicated yet.

At the start of 2020 it wasn't clear how long viral particles stayed airborne, and whether you could even contact covid from breathing it in, or if you needed physical contact of some sort. I remember one scare where people were worried you could catch covid from the cardboard used for amazon packages - before we realised covid dries out and dies if it lands on materials like that. Thats not true of all viruses.

Government policy, science and software share something in common: They can happen fast or happen well. You can only pick one. Rushed science gets small things wrong. Rushed software is buggy and brittle, and rushed government policy makes mistakes.

Its easy to forget, but the start of 2020 was a madhouse.

In the early 2020s, studies have shown everything and their opposite, so you can cherry pick anything that supports your view. I find it was a particularly interesting time because it showed how "messy" science really is. In normal times, you typically don't see scientific results before you have at least some amount of certainty. Some research get through the cracks (ex: LK-99), but not to the extent of what happened in the early days of the pandemic.

Also covid and other diseases spread well in open air summer festivals where UV is at its peak. And for covid specifically, we had peaks in the summer, where, again, people tend to get out and UV is high.