Final answer:
In the text, the reasons discussed for why friendships end include lack of proximity, lack of autonomy, boredom, and rule-breaking. The reason NOT discussed in the text is weak social ties and a lack of social control.
Step-by-step explanation:
In the text, the reasons discussed for why friendships end include lack of proximity, lack of autonomy, boredom, and rule-breaking. Therefore, the reason NOT discussed in the text for why friendships end is weak social ties and a lack of social control.