1. Hindered recovery and painIf you agree to be friends with your ex, you will face a more
difficult recovery process. Your hopes for reconciliation will keep you from moving on, and you will inevitably witness your ex dating other people. This can be incredibly painful and make it nearly impossible for you to heal and find happiness.
2. Zero chance of getting them backWhen someone breaks up with you, your subjective value in their eyes is already quite low. If you agree to a friendship, your subjective value will drop even further. To restore it to a level that could potentially win them back, you'll need to employ the no-contact or ignoring strategy.
3. The danger to your future successAccepting a friendship when you desire a romantic relationship can sabotage your future success. Your brain constantly evaluates your position within your social circle. If you allow yourself to be treated poorly or accept a lower status, your subconscious will adjust your decision-making accordingly. This diminished sense of self-worth will hinder your ability to pursue new relationships, secure better jobs, or achieve general success. You may find yourself feeling unworthy, experiencing imposter syndrome, or lacking confidence even when you accomplish your goals.