Even though I rate this drama higher (8.5), I agree with everything you said. Like you said, it started off so well but fell off in the latter part. They tried to do too many things without actually developing the romance of the leads much—so disappointing. The only part I differ in opinion from you is the acting of the ML. I really enjoyed the performance of the ML. Although the arrogant boss trope is tired, he played it comically and playfully. And ultimately, he was rightfully humbled and realized what he missed out on with Ning. By the last few episodes I was more convinced of Lu’s affection for Ning then vice versa. Although Ning still clearly liked Lu, it seemed like she still would’ve been happy and satisfied without a romance (which practically speaking isn’t a bad thing, but just isn’t the passionate romance I had hoped would develop.) To be honest, I may also be partial to Lu because that actor was the ML in Legend of Shen Li which I adore. Had I encountered him in this drama first, I may not feel so strongly.