Anti Armor

I’m just getting back into 40k, I haven’t played since 8th/early 9th edition. I was looking through the index and noticed that it seems like against high toughness armies it’d be hard to get consistent wounds. I used to run some predators in my list but they don’t seem to be in the index anymore. I was thinking about getting a knight to sit in the back and shoot as the rest of the army teleports up the board. What do y’all use to deal with vehicles?