PSA: You can't win a game by just splitpushing
Just had a Teemo top who almost never fought with the team and instead just was off farming by himself. He was split pushing basically the whole game and would always push too far into the lane and would get caught. Even though we were super ahead (I was 9/1 with Pantheon at one point with no smite jungle) the game ended up dragging for far longer than normal, as Teemo never fought with us for objectives. We ended up trading quite a lot of kills but with no organized push, they managed to drag the game out for 15 mins or so longer.
We also had a Lucian, who was acting similar to Teemo. Always by himself, constantly getting caught, and getting greedy for kills and just barely missing them. There was this one instance where he chased this Rek'sai all the way to their base only to die to their whole team.
Seriously, when a team tells you to group with them to push, try listening. A giant creep wave or free tower is not a subsitute for ending the game and winning.
Sometimes, it's appropriate to splitpush, sometimes it isn't. Please learn to distinguish when it is and when it isn't.
in the OP was clearly doing it wrong
HAR HAR HAR HAR HAR