To turn a wrestler/grappler into a fluid striker usually takes some time and a strong work ethic (TJ Dillashaw, Rafael Dos Anjos). Sometimes it will take more than 1 camp to see all the progression.
But conditioning is something that can be fixed relatively quickly and there are fighters from the journeyman-prospect level(Marcin Held, Warley Alves) to the championip level(Aldo,Mcgregor) that allow cardio to cost them wins. Fighters like Max Holloway and Tony Ferguson have used Cardio to enhance their other skills and become a champion level fighter It won't win fights alone obviously, but it seems like an obvious thing not to overlook.
Why do fighters let conditioning get in the way of achieving their potential?
I didn't find the right solution from the Internet.