I am trying to work out why I agree it’s not quite right as a maxi.
I am not advocating for traditional MOB/ MOG looks. However the OP will be in the central wedding party and lots of pictures. I am thinking the issue is that Bride and her bridesmaids will probably be in full length dresses. This is why I think it is a jarring image. She will look like a bridesmaid and her dress may well clash with any vivid colour they are wearing.
I think maxi dresses have had their day anyway and only worked as a casual or formal wear look. There is something American about wearing a full length dress to a wedding anyway.
From a wear what you want aspect, my opinion would be the maxi style is outdated and the frilled tiers don’t work for me. Maybe if I was tall and willowy this look would be more my thing.