Minions are the only thing standing in between you and the enemy nexus.
Minions increase the damage a tower takes by them being close to them.
Without minions you would not be able to finish the games.
If you go through my chat history, mind you it isn't the cleanest of chats, one thing I constantly say is "CLEAR THE FUCKING WAVE!!!"
Nothing pisses me off more than than my teammates just freaking standing there as they get their tower chunked or slowly getting themselves set up for a dive.
At that point, who cares if you lose CS your main job is to protect your tower and you know how to do that? CLEAR THE FUCKING WAVE
Build a tiamat, rush Static Shyv, do what you must, but CLEAR THE WAVE and PROTECT YOUR TOWER!
Now, in your case, basing on the fact that you have 23 kills, I assume you could have ended the game 10 minutes earlier but you wasted too much time abusing the enemy team, therefore you weren't farming, therefore you werent pushing waves, therefore you never attacked a tower or a structure at all.
Minions help take towers, minions give the same amount of gold kills do without the effort.
Push a wave, forget about the kills, and watch what happens to your game and grade.
I've gone games where I've had little to no kill participation (0 assists) but I got every tower, every dragon, every inhibitor while my team chased the enemy team around, and guess what? At the end of the game, my 10-0-15 adc gets an A while me being 3-0-0 with 250 cs in a 25 minute game gets that S+.
It's not that hard, I usually get an S every time I jungle.
JUST FINISH THE GAME