You may not remember this, but about 40 years ago 16mm was a home movie format that was usurped by 8mm (standard 8) than again by super 8 with the larger frame size.
Suddenly 16mm became too expensive and so everyone shot 8mm.
It seems the same thing has happened again, 8mm is too expensive for home use (not to mention too inconvenient - wow setting up the projector and a screen makes it inconvenient - I rather thought that was a fun part of watching home movies), and now home video rules the roost.
Home video is evolving even faster. First we had 1/2 inch tape porta-paks, then 8mm tape, then 4mm tape, then 4mm digital, now we have CD recorders.
Whew!
Graham