For me, I started to get put off when the writers started giving Annika insecurities about her looks while Shivaay was portrayed as a catch despite the fact that Surbhi looked better on the show as Annika over all.
I guess this is where the differences between Indian and Overseas beauty standards come to play (I am from a place where female Indian beauty means clear dusky skin, full lips, and curves; not fair skin / thin / short), but as this show generated a lot of income for Star Plus overseas it would have been nice for the writers to at least consider us!
I finally switched off during the ep where she had insecurities about Shivaay leaving her when she got older. It was hard to swallow considering Surbhi looked like a supermodel even with white hair, while Nakuul looked at least 10 years older than her.