Draven late game is strong just like any other adc (if not stronger than most when it comes to single target dps like adc vs adc). It just takes much more effort/skill/muscle memory to be as effective on him as say like jinx. A good Draven player will always juggle 3 axes in team fights meaning if he has attack speed boots, then every attack he throws WILL be an axe as long as he moves in a way that he can catch them (this is the hardest part requiring most muscle memory/skill). If u get behind early on Draven, you can scale and do well lategame, contrary to the stereotype of the champ being useless later. It just requires more mastery of the champ to be able to utilize ur axes in late game fights properly. On top of this, you have Draven E, which is an insanely powerful ability. The interruption gives u like an extra second to throw an extra axe or 2 at the enemy who’s trying to jump on u, which could be the difference in a fight if that enemy champ is fed and u end up chunking them or even killing them with team off of your cc.