Regarding calling something a conspiracy theory or saying that shadowy figures did a conspiracy, such shouldn't always be considered derogatory statements or dismissals. That is because we know that some conspiracies did in fact happen. For some examples of such consider the following.
We know from archaeology that the inscriptions of the names of some ancient rulers have been removed from stone inscriptions and that names of other rulers have been inscribed in their place. Similarly, consider what is said in the book called Negating the Image: Case Studies in Iconoclasm . It mentions that inscriptions of the name of queen Maruaten were replaced with the name of her eldest daughter. Consider also what happened to the name of ancient Egyptian pharaoh Akhenaten after he died. https://en.wikipedia.org/wiki/Akhenaten says "Akhenaten's monuments were dismantled and hidden, his statues were destroyed, and his name excluded from lists of rulers compiled by later pharaohs." https://www.worldhistory.org/Amarna_Period_of_Egypt/ says the following.
'Horemheb razed Akhetaten and dumped the ruins of the monuments and stelae into pits as fill for his own monuments. So thorough was Horemheb's work that Akhenaten was wiped from Egyptian history. His name was never mentioned again in any kind of records, and where his reign needed to be cited, he was referred to only as "the heretic of Akhetaten". ...
Akhenaten's name was lost to history until the 19th century CE when the Rosetta Stone was deciphered by Jean-Francois Champollion in 1824 CE. Excavations in Egypt had unearthed the ruins of Akhenaten's monuments used as fill, and the site of Akhetaten had been mapped and drawn early in the 18th century CE. The discovery of the Amarna Letters, along with these other finds, told the story of the ancient 'heretic king' of Egypt in the modern age where monotheism has become accepted as a natural, and desirable, evolution in religious understanding.'
For another example see https://www.bbc.co.uk/history/ancient/egyptians/hatshepsut_01.shtml . It says the following.
"Soon after her death in 1457 BC, Hatshepsut's monuments were attacked, her statues dragged down and smashed and her image and titles defaced. The female king vanished from Egyptian history. She would remain lost until, almost three thousand years later, modern Egyptologists reconstructed her damaged inscriptions and restored her to her rightful dynastic place."
The USA government also even committed conspiracies. Note that https://academic.oup.com/book/25369/chapter-abstract/192461943?redirectedFrom=fulltext mentions a book published by Oxford Academic which lists "... the revelation of real government conspiracies, notably CIA assassination plots, the Watergate scandal, and the Iran–-Contra affair."