They wanted to conduct a science experiment on the human population. Because infectious disease knows no borders, they knew for sure it would have to be a global one. 

They had every detail worked out in their models. They knew how far apart people would need to stand. They knew that the best way to stop any common virus from spreading would be total isolation of the whole human population insofar as that was possible. Families could not do that of course but they figured that they could live in different rooms or simply stay six feet apart. If they couldn't do that, they could mask up. 

It goes without saying – but they said it anyway because their models told them so – that indoor and outdoor venues where people gathered had to be closed (those were the exact words issued by the White House on March 16, 2020). The scheme was deployed first in China, then Northern Italy, then the United States, and the rest of the world fell in line, all but a handful of nations including Sweden, which faced many months of brutal criticism for allowing freedom for its citizens. 

It's truly hard to imagine what the architects of this barbaric policy believed would happen next. Is it as simple (and ridiculous) as believing that a respiratory virus would just disappear? Or that a potion would show up in time to inoculate the whole population even though no one has ever successfully come up with something like that before? Is that what they believed? 

Maybe. Or maybe it was just fun or otherwise remuneratively advantageous to try out a grand and global experiment on the human population. Certainly it was profitable for many, even if it wrecked the social, cultural, economic, and political lives of billions of people. Even as I write those words, it's hard to believe they are not out of some dystopian fiction. And yet this is what happened.