I think the most important debate: 100% defense vs 100% offense
In the current game of league, this debate is so flipping one-sided that there is zero point to going to the other side. 100% damage always completely destroys 100% defense and that isnt how shiz should work. If I am building resistance to their damage, and they counter it with penetration, or what have you, thats fine, but they should also be taking max damage from an ability or whatever. If an adc or kat or whatever can kill a tank in under 3-4 seconds, then the tank should be able to kill the damage dealer just as fast. 100 + 0 = 100, 0 + 100 = 100. The winner of the fight should be the one who outsmarts the other. Not because Riot as overly amplified damage to the point of 3 second teamfights and trying to get games over by the 15 minute mark. This still goes back to the "we need to shorten games more and more" and the only really way to do that, highly unbalance things to favor one side or the other so there is no tussle.