Some relationships become healthier the moment they become memories.

Some relationships only become good once they are over, when the affection can exist without the friction that came with proximity. You can appreciate someone genuinely from a distance in a way that was impossible up close. That is not a failure, and it does not retroactively spoil what was real.

If you keep considering reopening something, ask what specifically would be different this time. If nothing, let it stay in the past where it works. Keeping the good part sometimes requires keeping the distance.