There's still no reason to pick Kog

ADC Kog, I mean.

When he's not getting beaten into a mudhole by Riot's nerfbat, there's a reason to pick AP Kog. Superior artillery range sustained damage. That's an actual reason to pick a champ. An actual niche. But Riot hates that niche, so what are you going to do?

The only reason ADC Kog ever gets picked (aside from his diehard fans) is because he's statistically over-tuned. This is just as true now as it was when Machine-Gun Kog was at the height of his power. Neither live Kog nor Machine Gun Kog really does anything, aside from oodles of damage. If he's ever going to be an actual niche pick aside from the times when he's over-tuned, he needs to be doing something aside from all the damage.

Speaking as a Kog main since his first free week?

He should be the team-focused Tank Buster. He should be the damage amp Marksmen. He should have way more of his power budget devoted to shredding enemy resist (both flat AND percentile, I would argue) even if that means his stat-check button needs to be nerfed to compensate. That would be a real role for him. A real niche. Amp his team's damage by annihilating enemy resistance. That could be used to make a lower damage team more threatening OR help Mages/Assassins decisively remove priority targets.

It would be an actual niche for Kog. An actual reason to pick him beyond 'welp, Riot broke Kog again'.