This is the crux of the matter.
Betamax was a superior format over VHS, too.
8 Tracks made it to market first with 'better' sound. It really wasn't til the very late 70's that cassettes finally pulled ahead of the 8 track, and only because the cassette deck finally made it into the mainstream as far as homes and autos. The 'average' person didn't have a component system back then, they either had a dinosaur console stereo or one of those all-in-one piles of junk with the BSR turntable with ceramic cart, radio and 8 track player, and a pair of craptastic full range speakers. When *those* systems started to include a (admittedly crappy) cassette deck AND when car stereo manufacturers started to offer cassette options in large numbers, that's when the cassette took hold as more than a 'tape recorder'. This transition caught momentum with the mainstream around 1978 or so.
I agree. I came of age during that time period. My first car, a 1972 Chevy Vega, was purchased by me used for $500 in 1977 (and you think cars depreciate quickly today)! I put a very cheap cassette deck in it (don't even recall the brand, might have been Sparkomatic) with a set of 5 1/4 inch Radio Shack speakers in the doors (back when you had to cut the holes and run the wire, since no manufacturer put speakers in door panels then). I worked at Radio Shack and bought a set of Minimus 7's for the back deck (later stolen and replace, stolen and replaced).
My buddy had 8-track. We both argued over the format; you could get more pre-recorded tapes in 8-track at the local record store than you could cassettes in 1977, so he wanted to go with that. I was an early adopter, I thought cassettes were superior, and yes, because you could reverse them and also because you could more cheaply record on them.
By 1979, when I graduated from high school in Colorado, 8-tracks were clearly on the way out. The war was over; although 8-tracks would remain available for a long time after that.
The victory didn't last long. When I was in the USMC in Okinawa, buying my Luxman and AR stuff, I pondered over the 'new' format, called Compact Disc. That was 1983. I decided not to buy it and stick with cassettes. By the time I got back to the states, it was clear that CD was going to make it as a format, and I bought my first CD player, a Toshiba, when the prices started to drop into the reasonable level; I paid $79 in 1988.
I also decided not to get into DAT; a wise decision. I did get into MiniDisc. Oops.