If you look at all the religious megaliths we have today, like the Vatican or whatever, the reasons those exist is because they were built using several hundred or even thousand years of accrued wealth. (And a significant amount of 'reappropriated' building materials.) If the second temple really was built in 586 BCE, does it make any sense whatsoever that that could have been built with only 3 generations or so of accrued intergenerational wealth? That just doesn't seem plausible. Even assuming the bible is 100% made up, common sense suggests the longer biblical timeline is probably closer to the truth.

If they'd instead stumbled into Dubai-style wealth from these copper mines or whatever only a few decades earlier, surely that would have been written down somewhere.