Not at all, I'm engaging in good faith here.
> This seems a bit strange to me... so the Romans believed in supernatural beings, and the Christians also believed in supernatural beings (and of course so did the Greeks, and the Persians, and the Babylonians, and the Egyptians, and...); but instead of this being evidence that there were supernatural beings of some sort (with some people maybe being closer to the truth of the matter than the others), you decided this was evidence that there weren't supernatural beings?
This is a common misinterpretation. Rather it made me rethink why I thought Zeus was a myth and my God was real and that led to me realizing there was no evidence that God was real, I had been taking it on faith.
If there is one thing the explosion of popularity for fantasy stories has shown us is that it is really easy for people to invent the supernatural.
> If the entire world were atheists except Christians, wouldn't that be far stronger evidence against the supernatural? The fact that the Romans believed in the supernatural and the afterlife is evidence -- weak evidence, I grant, but evidence nonetheless -- that the supernatural and the afterlife exist.
Many people believe that vaccines cause autism. There is no evidence that it does and I don't lend the theory any credence. Lots of people believing in something says very little.
But at a basic level, religion has numerous aspects that make it useful, good and bad, to people in general and people in power in particular. Christianity has long been used to manipulate and control for instance; but it also provided community, a common moral code (again, good and bad), shared joy in weddings and births, solace in grief and purpose.
> What would satisfy your requirements for a "verifiable miracle"?
In an age where everyone has a very high quality video camera in their pocket the sasquatch, the loch ness monster and other such things have mostly disappeared but miracles have not appeared.