>>52489484Landorus has 2 immunities, Intimidate, 14 more base attack, better speed and special defense, and a wider movepool before getting spayed by Gay Freak in Gen 9. Great Tusk is great, it'll probably be better than Lando-T in Gen 9, but it won't be as good as Lando-T at its height, even if only slightly.
No Toxic, Swords Dance, Explosion, Defog, or U-turn guarantees that it'll still be shy of peak Lando. If Lando gets Toxic, Knock Off, or Defog back, it'll still be #1.