I never said "no other person in history" could do what Curry did...I was more referring to what you said...that only a handful of players have the talent mixed with the dedication to do what Curry, Jordan, Dream, etc. do/did. There are a lot of "elite" players in the league. However, there are only a handful that will truly be remembered throughout history because they were on another tier. Some of those other elite players work just as hard has Curry, but they aren't him and never will be him.
This discourse started when you said "skills can be attained." They can, but only to a point. Some guys who are very high level players can work on post moves for countless hours, but they will never be Dream. Some guards can work on their passing, but they will never have the ability to pass like Magic. Some players can shoot thousands of threes, but they will never be able to sink them from the spots Curry can at crucial times in a game. Kawhi Leonard is a great example. He's taken the talent he has and worked hard, transforming himself into one of the best players in the league. He'll carve out a nice career...and might even wind up in the Hall of Fame. He'll be mentioned in same breath as a lot of great players, but he'll never be Jordan, Dream or even peak level LeBron.
Will the next Magic/Dream/Jordan show up? It's always possible. People win the lottery all the time against unbelievable odds...but I'd say it's close to as likely as me hitting the jackpot if I picked up a ticket tomorrow.