Why don't people understand?
Excluding professional games above diamond, games are won and lost in the first 15 minutes. You can claim "oh but once I won a game after being behind for 45 minutes!" great. That is what we in the statistics field call an OUTLIER! You should go look it up before you use this argument.
The reason I say games are won or lost in the first 15 minutes, is because within 15 minutes, you are accurately and correctly able to identify who the superior players are. You are able to judge from CS, general positioning, map awareness, and their interest in objectives, just how much better they are than you.
If you're in bot lane and the enemy is 4-0 by 10 minutes... guess what.. THEY ARE BETTER THAN YOU! They will continue being better than you for the entirety of that game. They will not magically stop being better than you and make the one fundamental mistake you know how to capitalize on.
Please, stop deluding yourself into thinking you have a chance when it's 25-0 before 20 minutes. Just stop wasting peoples time and surrender, so you can reroll matchmaking and hopefully get a balanced game.