I do not have a very long neck and jumpers with round necks don't suit me really. I have tried. I am also overweight, have done a lot of strength training and have a double chin, so there my neck is wider and disappears.
What I'd like is options for some necklines that are still round but wider. Not ones that look deconstructed or boat necks, just where I don't look or feel strangled. Bearing in mind what is round on a normal person will be tight on me. I also like voops and u necks - never understand why they are not more available. Cotton, cashmere, lambswool preffered.