I think that with all things being equal an aero frame helps, but it’s a really small gain compared to body position / bar width. Should be on the order of a 40mm wheelset vs. a 65mm one. The fork is another thing as well, but either way the aero difference is pretty small. Of course it doesnt help that most frames see very little aero development unless you are shopping the frame models raced in the WT.
To me the advantage of these are more than just weight. The round headtubes with a standard 52mm upper / lower bearing and use of round seatposts should make them easier to live with and replace parts. I think it’s also easier to design frames that limit lateral and torsional flex with round tubes vs. aero shapes, particularly those with cutouts, etc.
