As frustrating as that kind of pacing is, we really shouldn't hold it against the writers who do that. I can't really cite why I feel this way at the moment, but I think that a manga's popularity tanks the moment the OTP is resolved. I'm a will they won't they enjoyer and many times I have lost interest shortly after the main couple gets together. And if there's a harem, the rabid fans of the losers can get out of control. Sometimes it's in the writers best interest to cockblcok the MC as long as possible.