Its true that vision wins games. Dont know how many times I said it in matches last season, but its more than I have fingers and toes, and less than I have hair on my head.
So what they did.... was since vision was so hard for the average player to wrap their tiny tiny mind around, they lessened vision all around.... sorta.
For those who try to use vision to its fullest, theyre still rewarded with all the benefits it brings. Since there is less vision, what vision you do have is more powerful.
I just want to point this out. Pinks
were reduced to the cost of stealths from last season.... but you still dont see people buying them other than support mostly....
Anyway... vision up time is lower, but more available, so if you want to invest in it you will have to put in more effort, but you reap potentially greater rewards since your opponent my not invest in it, and could lose objectives, lanes, lives, matches to the failure to invest.
Vision is powerful, they lessened vision overall, but made what you get more precious, therefor creating some balance on it.
Think of all the "MY CHAMP HAS COUNTERS AND ISNT OP, WHY 4 U NERF MY CHAMP" threads, and compare them to the crying over vision reduction. People who were having success with vision wanted to keep it.
Vision was freelo, they nerfed it. Not because it by itself was OP, but in part because of how hard it was to come back when you cant go anywhere without the enemy seeing it, and cant even safely ward to see the enemy....
Then they invented this thing
to help people get out of their base and chase the deep warding supports/junglers out of the bushes.
Bottom line is, WARDING ISNT JUST THE SUPPORTS JOB! If everyone learned to ward diligently, and well, then fewer games would be lost because of people who cant ward.