It's been my observation that when a lot of people think of cults, they imagine something temporary. A founder starts something, people join up, a few decades to by, the founder dies, the group falls apart.
In practice, this is often not the case. Cults can survive the death of their leaders, and depending on the circumstances, can even be made (at least temporarily) stronger for it. They often last long enough to form splinter groups, sometimes with new members of the community stepping up to take the leader's place, sometimes not. And then those groups can last another few decades before splintering off again, restarting the cycle and keeping the horrors alive for another generation. Sometimes they don't need to splinter, because they've picked up enough momentum to be self-perpetuating, a successive series of replacement leaders keeping the momentum going.
Cults can go back centuries. And this is something that is so, so important for people to understand, because often when they hear that you were the victim of cult abuse they assume that you were inducted into it - and of course, that does happen and is no less horrible, but it's a markedly different experience from being raised in it from the time of your birth.
Being taught nothing, nothing, outside of what the cult teaches and the bare minimum needed to survive.
Internalizing, as a child with no independent access to information, the message that you need the cult and would be irrevocably doomed without it.
The horrifying trauma, when you finally discover (if you finally discover) that it's all bunk, of realizing that your entire life up to this point has been built on a lie. The years you spent being miserable, being terrified, doing your best not to fall from the cult's graces, were all for nothing. Wondering what you could have been and done during that time, and knowing that it was stolen from you and you will never get it back.
Literally not knowing anyone outside the cult, and having to find your own way despite the fact that your parents deliberately never taught you how. Having to completely rebuild yourself as a person, because who you were before this point was a creature built to serve, not to think or make choices or grow in new directions. Having to accept that a world you were taught to fear and despise is the only place where you really belong, and adjust to living in it and not shrinking fearfully from every stranger who crosses your path.
And when you try to talk about what happened to you, no one understands. They can only imagine a childhood like their own, born and raised with the freedom to choose, and they act as if you somehow chose, as if the people who indoctrinated you presented your infantile self with two equally well-argued possibilities and then simply urged you to pick one in specific. They see the cult from the outside, and of course it's ridiculous, of course it's horrible, why would anyone willingly submit to that?
No one does. Cults don't run on willing converts, they run on deception and coercion. Imagine that all that started before you were old enough to walk, and was the only life you knew for the first twenty years. I didn't choose to be a cult member, my mom quite literally picked it out for me.
I did get out, eventually. It wasn't a matter of being smart enough; it was a combination of luck, unmonitored Internet access, and some of the very traits my parents drilled into me backfiring on them hilariously. Not everyone is as lucky as I was. Not everyone has the means and the incentive to find their way out. My parents were born into the cult and they will die in it.
That might be what hurts the worst - losing the people who were my whole world as a child, because they're too afraid to consider that they might have been wrong.