GP should only lose base health or suffer orange nerfs, not both. Ult should be left alone.
One thing you need to keep in mind is that when gp teleports, he legit has to be really far behind the enemies and take time to set up barrels. Aside from them, he has 0 cc and will do nothing except parrrley people every 4 seconds. It's pretty stupid. Gnar tps, he has a giant ass stun... ekko has super slows and a stun... teleport is so much more useful on everyone else. The only thing allowing him to have the global presence a top laner should have is his waveclear and ult. There are some times where an enemy barely lives with a small amount of hp, now his ult will be nothing unless someone is stunned in the middle of it or is stupid enough to stand still for 1 second and get smashed by the deaths daughter which you receive LATE GAME where he's SUPPOSED TO BE STRONG. The orange actually has a little delay so it can screw you over in some situations. I've played gp a lot, and looking at the ult nerfs.... People walk out of the ult so easily until, again, LATE GAME where he's SUPPOSED TO BE STRONG. Nothing too big happens, it just shoots faster so the slow is applied a bit more. Just because he's strong late game doesn't mean his laning phase should be super shit. It's not enjoyable if you have to sit and farm even safer now because of these nerfs because the darius will kill you as soon as he grabs you. Riots basically just saying; " here, this champ is strong. now we want you to farm more and be the enemies bitch until you get triforce " GP has a very big cooldown on barrels early and his laning phase is based off trying to play the enemies with barrels. Considering gnar, quinn, people with dashes, lucian etc that sometimes go top, he basically never lands a barrel unless it's in the fog.