I like Kreia, and she is arguably one of my favourite characters across most media. But the aforementioned several hour long video essays really misunderstand her core philosophy and narrow her down to why Randian hot takes are so true or take her for a nihilist (while also misunderstanding what nihilism means). Both of which are objectively wrong and just come across as a weird way to justify why she was right.
She wasn’t. The whole point is that while she’s a wise and experienced teacher, she’s weighed down by her own biases and betrayals she has endured which made her bitter and disillusioned. Being betrayed twice by both sides made her want to wipe out them both. She tries to be impartial (and sometimes is on the trail of the right idea), but often fails at it, and the biggest takeaway from her teachings is that you need to think for yourself, not blindly follow the teachings of another in a vein attempt to please them. You’re literally told off at one point for just parroting Kreia’s own talking points back at her.
The whole show down on Malachor boils down to her wanting you to challenge your beliefs and test them in order to find out your true values, and finally forcing your hand if you refuse. She wants you to hear her teachings, discard what you believe to be untrue, and become better than she was.
Because Kreia was wrong. The ultimate message of Star Wars is hope, and she embraces that in the end (at least in the canon Light Side ending). You are the hope.