What amazes me about Masada is that no one else than Josephus seems to have known about it at the time or shortly after. The Roman Legions never mentioned it.
And yet, Flavius Silva's ramp still largely remains intact up the side of Masada.

We have no idea what they wrote. We only know what survived. In the aftermath of the Year of the 4 Emperors the Roman world had a lot more pressing issues than a small bunch of rebels in far off Judaea. The empire was bankrupt, the capitol was nearly burned to the ground in the final battle and there were revolts or the aftermath of revolts to deal with in Germany, Gaul and Spain.
No one gave a flying fuck about Judaea.