Well you just shot PGS out of the water.
Sure. But there's a difference between prevention and reduction. As i said - worked Great for the first one (the source you posted seems to claim it prevented it ) - but with delta it did a solid but less effective job. As per here:
Yet another study has found that the authorized COVID-19 vaccines greatly reduce infection. Let's take a look at this latest paper in the context provided by previously published research on vaccine efficacy.
www.acsh.org
You still got breakthrough infections with delta. It couldn't prevent all transmissions. AND - if someone DID get infected obviously they could still transmit the virus, tho they tended to be contagious for a lesser time.
So - reduced transmission. But not no transmission.
So when you say it did nothing that would be completely and utterly wrong for delta. It did much. But it did allow some transmission, more so than the original.
It does nothing against omicron at all as far as transmission goes. But - we agreed on that already i believe. And omicron is not the threat that original or delta was.