This arc isn't wasted IMO... I think it's meant to allow Karen to realize being clingy and overbearing is annoying AF so that she grows and can actually be someone Mi-kun would want to be with.
@Serathe7 Abel is his name and im guessing earl is his title. Often times aristocrats will hold several titles... and since able will not inherit his fathers title of duke until his dad dies... he would granted a a lesser one like earl until then... and since his aunt is an uptight bitch I...