Adding to the discussion about how to convince a conspiracy theorist/why people believe these things, here’s my take on it: Mosh said that people feel they have been lied to. It seems to me that there are basically four reasons to feel that way,
1. someone lies all the time and you wise up,
2. you yourself (or your group) lie a lot, and you know this, but you can’t square it with your view of yourself (or the people you care about), so you push it on your opponent/the other, because that way, you feel like you’re fighting against lying, so you can’t really be a liar.
3. you feel inferior, you believe that you can never get the other to respect you like you (against your will) respect them, because deep down, you do not respect yourself, so you fight this by indulge in a fantasy about how they wrong you so grieviously that you then have the superiority of rightousness.
4. you gain advantages (prestige, love, financial rewards, influence) from agreeing with the enemy/friend paradigm of your group, and you’re insulated from the cost (this is why homophobia diminishes when people are confronted with actual out gay persons).

If all these are factors, then giving information can only work on 1 and partly on 4. But sometimes, the boost of confidence a conspiracy theorist gets from accepting a piece of actual researched information allows them to overcome 2 and 3 (rarely to the point of acknowledging them as factors when looking back), and praise for these people changes the math on 4.