I'm so sorry to hear that. Good you managed to get out, and I would agree that a healthy family without a dad is better than a toxic family with a dad.

While gaslighting may at first glance seem a tad silly, as thought it's just dumb pranks, and the harm of it is perhaps not immediately apparent, it is a tactic commonly employed by abusers. (I guess it is abuse in and of itself? No matter, that's semantics.) The idea is that if your abuser causes you to trust their judgment over your own, they can get away with more and more horrible shit.

"No, silly, I didn't hit you, you hit your head on the cabinet door, remember?" "I know your friend told you I'm bad news, but I think she's actually bad news so maybe you shouldn't hang out with her anymore." It gives the abuser a tremendous amount of control over the victim's life.