i don't think it is wasted film at all david i think it serves a purpose.
how could something with a use be a waste ?
its like saying that because care tire treads are only on the surface that touches the roadway
it is a waste of rubber + materials to make the sidewalls out of rubber, or because the tire makes a seal
on the rim, all tires should be tubeless, and it is a waste to have an innertube.
time and effort have created things to be as they currently are because other ways did not work as well.
they might have worked in some applications and situations but the benefit outweighed the cost.

im just glad that kodak didn't have a proprietary 35mm design specifically for their 35mm cameras .. a different
drive / transport mechanism, a different type of sprocket holes and canister size &c. they stopped making 35mm cameras in the 60s? 70s?
and they would have had to retool their machinery to work with the other 35m formats. what a pain!

almost as much of a hassle as it is to deal with proprietary sizes for their 80 years with box cameras + roll film.
what a drag it is now to find spools and film and processing equipment / methodology when using an old folder.
at least 35mm is an accepted format, and a free for all ...