Matches finish too fast

Not sure why but recently the games on Summoner's Rift last way shorter than usual (not talking about game modes). Very often i see a 10-15 min breach in base and destroying inhibitors thus in my match history out of all games the one that lasted the most was barely 22 minutes. I miss the older days where games lasted for 40 minutes because i play late game champions that need some time to be effective.