If the game's a 3v5 from 2 minutes in, would you honestly wait beyond 20 minutes?

And it's not the positive kind of 3v5 you see in bronze where people throw so hard that the 3 are in an advantage. I'm talking a game where the opponent is literally waiting for waves to dive you since you think a no-farm adc is going to save the game after 15 minutes.

So why fight it?