If this sales pitch were applied at a mechanics shop, no one would go back, everyone would want a refund, and the shop would be out of business in a very short while.
Mechanic: Your car is broken. I will fix it for $50
Customer: It seems ok to me. see? it runs fine.
Mechanic: No, it's broken, I hear a noise. $50 to fix it.
Customer: Well, you are the expert. Here is $50.
Mechanic: Thanks (looks under hood, wiggles something, closes hood) All better.
Customer: I can't hear any difference.
Mechanic: That's because it's better.
Customer: So I can leave now?
Mechanic: No. I hear a different noise. $50 to fix it. Then you can go about your day.
Customer: What? Fine. Here's another $50.
Mechanic : Thanks (repeats initial process)
Customer: So now I can leave right?
Mechanic: No. There is another different noise. $75 to fix it.
This can go on forever.
How many of us would expect the customer to stay there and keep forking out money? And how many would expect passers by to weigh in on the situation and call the customer names when they have had enough of the mechanic shop and want to leave?
So why is it different when It's public health that says "No, you can't leave yet. Now you need a booster..."