Does IV really matter and which should I upgrade??

[BilalSaid]

Hi guys,I would like to know how much IV really matters and whether I should upgrade my 2004cp dragonite with hyper beam and 80% IV,or my 2029 dragonite with dragon claw and 50% IV?Help please!

 

[Neltharion83]

IV really matters and a pokemon with 50% IV should never get evolved.