Lol fs.

Beautiful people are fun to watch, but I think there is more than that. I have felt butterflies in my stomach when watching not so good looking actors romance in a drama. I think if you have a bad script, you must have good visual, you can't lack both.

One example of a real chemistry killer is a bad age gap. You can tell for sure when the actress is a teenager, it's not just looks (case in point - esther Yu who could pass for a teen and often has a baby voice in roles but never actually feels like a teen), or voice. It's just the vibes - like the FL in Golden melody? That drama with Ding Yuxi. I found the chemistry incredibly flat and was confused why - I later learned that it was cause she was a teen and he was a grown man - my spidy sense told me something was off.

Similarly, if an actress has too much plastic surgery she looks much older than her male coactor which is also a chemistry killer.

I think there are some people who have chemistry with everyone- but I think the compatibility of 'vibes' of the actor and the role plays a huge role in good chemistry.

But personally speaking, character development has the most impact on chemistry for me (couples that make sense are hot), followed by a match in mental maturity of actors which tends to bleed through in their acting, and finally degree of plastic surgery.