It is lovely OP and I’d quite happily wear it to some of the weddings I’ve been to. It is really odd to me that anyone can dismiss any outfit as not suitable for a wedding. Unless you think of weddings as one homogenous mass and there is only one correct way to do things, in which case, how boring. It’s surely a bit like saying is this outfit suitable for a “birthday party” or a “day out” - I mean who knows, way too many variables. Same with weddings, surely. Any other way is boring, at best, pretty stifling and disrespectful of your guests at worst.
Admittedly I do tend to just pick something from my wardrobe each morning including when I’m invited to a wedding. But I’ve been to weddings in jeans and a t shirt, polka dots, fancy dress (as in costume not a fancy dress), white, cream, heels, trainers, dresses - whatever the specific occasion called for.
i like the dress OP.