"You're a conspiracy theorist cult member."...
This is their defence mechanism taught to them by the mainstream media...
They cannot reject the proof of the arguments so they resort to dismissing you entirely as a way to protect themselves from being red-pilled...
This is what the mainstream media taught them to do and at some point, a red pill clicks within their minds and they become unplugged from the Matrix...
Once that happens, they can never go back...
Keep planting seeds, anons...
You never know which red pill will finally sink in for good and change their life forever...
We must not give up...
https://files.catbox.moe/yr26i7.mp4
(ULTRA Pepe Lives Matter)
It's because they don't have any data or proof to backup any of the claims they make, what they have is a perceived authority figure telling them things are a certain way. Anyone they perceive to have "less authority" will never convince them things are different since their beliefs are grounded solely in authority, data and logic are totally meaningless to them. It's very tough to break through to this type of person, thankfully right now the powers that be seem to be on a quest to discredit themselves, so these people are beginning to question the same people they previously perceived to be an authority.
Once somebody begins to trust you more than the original source for their beliefs, the red pill suddenly becomes palatable and the result is usually instantaneous. Like you say: once the red pill clicks you can't go back.