While the romance between Angel (David Boreanaz) and Buffy Summers (Sarah Michelle Geller) in the first few seasons of Buffy the Vampire Slayer was certainly iconic and beloved by many fans, it was also a deeply toxic relationship that held both parties back from developing as characters and people. In Season 4 of Buffy, and even more so in the first season of Angel, it seemed like the writers were allowing the two to let each other go and move on in healthy and mature ways. However, either due to fan demand or the desire to keep teasing them, the creators could not seem to let it go -- and it hurt both characters' arcs.
Source：https://www.cbr.com/angel-let-go-buffy/
