My son’s only 8 so I have no personal experience parenting a tween/teen. So take that into consideration with my advice.
How about the next time you’re watching with them, try this:
“I was raised allowed to moderate my own content because I was trusted to be intelligent and wise enough to critically select what I watched or read and learn from the mistakes I made if I consumed something negatively influential. I have tried to extend this same trust to you, but the constant repetition of what you hear and your inability to form a cogent argument makes me feel like your YouTube viewing habits are teaching you to accept concepts at face-value simply because they are popular.
If you will engage with me in a discussion on these videos, I’ll leave you alone and continue to trust you on this. However, if you continue to shrug and dismiss the conversation, I will have to consider blocking this content until you are ready to engage with me on a deeper level.”
I know modern parenting advice tells us to prefer reward over punishment so if there’s a reward strong enough to motivate them to engage, go with that. But if punishment is a greater motivator, I’d say damn the modern parenting advice.