if you put it like this I perfectly agree with you that Elizabeth was right in refusing Mr Collins. But I don't think Charlotte can be called wrong in accepting him.
Lizzy would certainly be very unhappy with Mr C and made him so in return, and she realizes that 100%. Whereas Charlotte, having other views and much more complying and reserved disposition, as well as virtually nule prospects, makes her choice "with her eyes open" and I think she clearly sees what she has to undure and will be the outcome. I don't imagine she depends on being happy with Mr Collins but she reasonably hopes to be content, secure and busy.