What magic system trope do you hate the most?

For me, it's hereditary magic. I can deal with random people not being able to use a setting's magic (though I'd prefer magic to be accessible to everyone), but I hate the weird vibes that scream eugenics to me.

Naruto

My Hero Academia

Harry Potter

Just to name a few, take something as cool as powers and magic and turn them into things where you end up with characters incentivized to breed the perfect people.

Like I get people like the idea of going all Gregor Mendel with fire dad and ice mom to make a cool fire and ice kid, but then it's just gross and I don't know. It makes me think back to when I was younger. How so much of your life could be decided before you were born. I don't know, it didn't make it fun playing pretend.

What about you? What magic system tropes did you hate?