I wouldn’t want to spend my life with someone, who would not be capable of understanding the things I like thinking and talking about, so a lot less intelligent partner would be a problem. I would also not want to feel like I have nothing to offer intellectually to my partner, so the ideal is to be in the same league. I can theoretically imagine some kind of combination of one partner being less intelligent but also outstanding in another department that the other partner is lacking.

Dont gotta be super smart, just have a good attitude and curiosity. I want to build a life together, not cure cancer.

I believe it depends on exactly what you define as “intelligent”

That depends on what you mean by intelligence.