According to Psychology Today, most relationships fizzle out because of several typical issues such as lack of trust, differences in expectations, and compatibility issues, among many others. Trust issues can occur due to infidelity, jealousy, possessiveness, lack of emotional support, and lack of mutually supportive goals, among other issues. Without trust, a relationship misses essential anchors to a strong bond; safety and security.
Relationships can also fail due to a difference in expectations between couples. Over time, couples' expectations in a relationship may differ as each starts pursuing their own goals and plans. Couples can also have compatibility issues that include missing intimacy, differences in personality types, and attachment styles.