Everything is in the title. I'm hearing more and more people (especially streamers) saying or hinting that "win lane win game" is not true anymore. But on the other side, games are shorter and shorter, now averaging 28 minutes in silver&bronze where people don't even know how to close the game (https://www.leagueofgraphs.com/rankings/game-durations#)
You could say that's a pointless question but I find it interesting.
If games are shorter because of snowballing well... snowball usually come from laning phase (kill in lane/roam/early ganks, sometimes from a huge farming difference.)
The only explanation I can come up with is : pushing is easier (which is true especially with baron's buff, but the team who take the first baron is usually already wining the game.)
PS: you may find some errors since I'm still studying English.