I saw a travel blog post recently that claimed that the Western Wall is the only remaining portion of the Second Temple in Jerusalem. At first, I thought this was just a mistake on the part of the blog post's author, but then I found that several other sources (including the Encyclopedia Britannica) say the same thing, though I couldn't find any that cited an academic source and/or explained their reasoning for making that claim.
So, my question is, is there some reasonable interpretation of the claim that the Western Wall is the only remaining portion of the Second Temple that is consistent with current archaeological and historical evidence? And, if so, what precisely is that construction of the claim?
Note that "Herodian-era" in this question means built in the time of Herod the Great, during his expansion of the Temple Mount in the first century BC, which was toward the end of the Second Temple period.
Some sub-questions that would need to be answered to answer that this question:
Is the claim that the Western Wall is the only remaining portion of the actual temple building from the Second Temple period or that it is the only remaining portion of the temple complex from the Second Temple Period?
If the claim is that it's the only remaining portion of the actual Second Temple building, was the Western Wall indeed considered to be part of the temple building? My understanding (having been there) is that the actual temple building is completely gone (demolished by the Romans when they sacked Jerusalem in 70 AD) and stood somewhere near the location where the Dome of the Rock stands today and that the Western Wall, while part of the temple complex, was not part of the temple itself, though perhaps this is where I'm mistaken.
If the claim is that the Western Wall is the only remaining portion of the Second Temple complex, what is the basis for the claim that it's the only remaining portion? How would this reconcile with the seeming continued existence of several Herodian-era (i.e. late Second Temple Period) portions of the Southern Wall and its Temple Mount entrance area and even older portions of the Eastern Wall (some of which, from my understanding, date from the Second Temple period, including both Herodian and pre-Herodian and some of which even date to the First Temple period?) The Western Wall itself is also Herodian-era, as far as I know.
So, a good answer would explain the basis on which the claim is being made and specifically why the remaining part of the Western Wall is considered to be a remaining part of the Second Temple, but the remaining parts of the Southern and Eastern Walls are not, despite apparently being built at the same time by Herod the Great during his expansion of the Temple Mount.
For those who may not be as familiar with the present appearance of the site, this is a relatively-recent aerial photo from Wikipedia. The photo is facing the Southern Wall. The Western Wall is on the left; the Eastern Wall is on the right. The whole area inside the walls is what is known as the Temple Mount.
Image source: Wikipedia
By the way, I'm primarily interested in what is supported by archaeological and/or historical evidence, though if the claim were based primarily on some religious tradition, that would be interesting to know, too.
Given that my question is mostly about the history of the temple complex in Jerusalem, I figured that the History Stack Exchange would probably be a better fit than, say, Skeptics or Mi Yodeya, but please let me know if you think this doesn't belong here for some reason.