Dmg is so high that you can't outplay broken champs anymore, because they literally have everything in their kits, they're tanky, they deal dmg, they have mobility, they have true dmg, they have healing, everything.
Your macro knowledge doesn't matter, your csing doesn't matter, your pathing doesn't matter, just pick meta sht and not something you enjoy (which in 5 years of playing I will never understand), you can win most of the time.
You picked Riven because she's broken as hell and have DD black cleaver ? congrats you're a tank now that deals one shot dmg. I picked Wukong 'cuz he was my first champ ever and still enjoy playing him ? Good luck trying to even get 1 cs.
I like playing Udyr but the enemy has reksai or hecarim or literally any champ with mobility ? Good luck getting anywhere near anyone.
And you can go on and on with that sht. You can lose against a whole division lower player, because he picked a champ that deals dmg in 0.5 secs and you didn't.