The concept is older than you think!
Section honey is honey that is produced in comb that has been built in it's own casing that has been provided by the beekeeper. The original sections were wooden and had square corners. The bees were reluctant not only to build the sections, but to build into the corners. In the 1880s there were articles in beekeeping journals about round sections, with an article in 1889 suggesting cutting slices through glass jars to provide something with which to contain the comb.
The modern round plastic section appeared in 1954. It was called "Cobana" and seems to have been designed by a Pennsylvanian beekeeper called Dr Wladyslaw Zbikowski, who not much is known about. I remember Cobana sections being advertised in the U.K. appliance catalogues, but they weren't popular. They were replaced later by "Ross Rounds" that are said to be the same thing, but I suspect are probably copies. They too, are not popular in the U.K. As auctioneer at the West Sussex BKA beekeeping auction for over 20 years and having attended every sale of its existence since 1975, I think I have only seen about 3 lots of round section equipment for sale.
In the U.K. sections have always been difficult to produce, whether round or square and they have largely been replaced by cut comb honey. In countries where the summer weather and forage is reliable, sections are still popular, especially as the price is about four times the price of the same weight of extracted honey. This is an attractive proposition for beekeepers who operate in areas where comb honey looks attractive, because there is less work, although the shelf life is a lot less.
Ross Rounds now appear to be the leading manufacturer of round section equipment and they claim that in the U.S and Canada 90% of comb honey is produced in Ross Rounds.