4. You think Grouping solves all of your problems
Your bot lane has a combined score of 7-21? Oh, that's okay, just group, we will let them get all the kills in the teamfight that we will SURELY win.
Enemy team comp consists of Sejuiana, Neeko, Kennen, Braum, and Vayne, with yours being Tryndamere, Udyr, Ryze, Ashe, and Lux? It's okay, go ahead and group, it's not like the enemy team just has to press R to win.
When you group, you are essentially distributing lane xp between a minimum of 4 people. The opposite of what you want to be doing. So why do it.