Hypercarry Curve:
https://i.gyazo.com/32b60ee5a62594f5aeb42f4395aff76a.png
Jinx's Curve:
https://i.gyazo.com/72649659852837253871254990722c9e.png
Hypercarries lose more games before the 25 minute mark and win exponentially more if the game lasts beyond 40 minutes. That curve has never been true for Jinx. Late game, the enemy team will have enough damage to just one shot her. If the game goes that late, she is extremely team reliant and it's basically a coin flip, unlike an actual hyper-carry (Vayne) that can consistently scale into an unstoppable monster.
Jinx is what I call a snowball carry. When she wins lane, she is essentially unstoppable for the next 10 minutes. She will shove quickly, dominate the enemy team, and end the game. That's her ideal power curve.
I'd like to correct another misconception about Jinx here: Her laning phase is not weak. Her early HARASS is comparatively weak, which is usually crucial to winning lane, but Jinx's lock down and finish during laning is incredibly strong. If you bring a competent Thresh, Blitzcrank, or Leona, that Jinx can easily win that lane.
So what if Jinx loses lane, because Lucian and Ezreal exist right now? Then if her team also lost lane she loses the game. She doesn't have any damage to bring to mid game teamfights and is still really vulnerable. If her team did well despite her, you can stall til late and see paragraph 1.
Edit: Closing Notes Here
I'd like to add on that you can argue that it's because of the nerfs that she's like this. That is objectively untrue. Before the nerfs she had the curve of a straight up early game champion.
56% winrate before 30 minutes, gradually sloping down as time goes on