I had the exact same thought recently. I guess they don't really exist as it kind of defeats the point of 2FA

What is the current understanding of whether they reduce spread?

I was a listener of Rogan from episode 1 but he has been getting consistently worse since 2020.

Your country is too politicised at the moment mate; hope it gets better soon. As bad as things are on the UK at the moment, the political divides don't permeate every aspects of society.