Answer:
I changed around some syntax in your reasons to make them stronger.
Intro:
Hook [eSports is becoming increasingly prominent in pop culture]. Thesis [therefore, eSports should be considered a school sport]. Reasons [cognitive: Problem solving & strategy skill development. Social Development. Entertainment and art.]
BP1: reason 1 [Cognitive: Problem solving & strategy skill development]. explain [it is important to develop these skills because...]
BP2: reason 2 [Social Development]. explain [it helps students develop socially by..... and it is important to develop socially because....]
BP3: reason 3 [entertainment and art]. explain [these are important because....]
BP4: counterargument [some people think eSports should not be a school sport because ______. But their reasoning is weak because _____]
Conclusion: restate reasons, then thesis, but phrase things differently than you already did to keep things interesting.