Childhood memories "Princess Pearl" Why are the first and second films so popular, and the third one is not good?

I believe that Princess Pearl is a childhood memory of many people. The reason why the first and second TV series are very popular, but the third one is not, is because the third one has changed actors, so it is not original and doesn't like watching it. I remember watching Princess Pearl, when I was still in primary school. When I saw Wei Zi and Swallow being bullied, I always cried unconsciously. My relatives and parents laugh at me every time I cry, but I think the plot of the TV series was very touching, so I don't understand why they laugh at me. I remember when the first movie Princess Pearl was released, I stayed in front of the TV every day and watched TV dramas immediately after finishing my homework. I am a child who doesn't like watching TV plays very much, but I haven't missed an episode of this TV play. When I just finished watching the second part of Princess Pearl, I especially expected the third part to be released immediately, but when I finally saw the third part, I found that the emperor had changed, and Wei Zi and Swallow had also changed. Suddenly I couldn't find the feeling of the first two films, and later I didn't like watching them very much. I think this TV series became an instant hit because the actors selected in the first and second films were particularly good, and the audience was already very impressed with the first two films. Suddenly changing actors will lower the expectations of the audience, and I don't think the replaced actors are as good as the first one. In this TV series, my favorite is Emperor Ama. I feel that he is particularly kind and handsome, but after the emperor has changed, I feel that I don't want to see it without the original handsome emperor. I think it's best not to change actors if a sequel is to be made, because changing actors will affect the audience's ratings and the audience's evaluation of this TV series. The TV series after changing actors is like a new TV series, which needs to be familiar with actors and plots again. I watched an episode and found it boring, so I stopped watching it.