And it did in two ways: the Temple was destroyed, which brought about the end of the old dispensation and Temple cult; they died, and so the end came for them.

You’ll read things like “The first generation of Jesus followers believed the Day of the Lord was IMMINENT. The theology eventually adapted to an ever-delayed Parousia.” out of the current post-Christian textual critics, who have little in common with Christians except they like to denigrate the Faith with clever textual punditry. In other words, Christianity is a effectively a hoax.

Pish posh. Sure, some percentage of early Christians believed all sorts of things, but that was never the content of the faith. If you stick to the Apostles you won’t find them writing that the End was imminent but that their own end was imminent, at a time and place no man knew.