A lot of people thought that the 126 Instamatic cartridge would kill 35mm: it was easy to load, you didn't ruin the whole roll if you accidentally opened the back; it was less likely to jam, and so on. Plus you had the window on the back so you could see which kind of film you had loaded and where you were on the reel.
It captured the point-n-shoot market and finally finished off the old roll-film Brownies, but it didn't kill 35mm; there are a number of reasons, but I think a big one is that the quality camera makers didn't make high-end cameras which took 126; they just made better point-n-shoots.
Olympus made this Quickmatic, a nice camera but still a point-n-shoot. It's auto exposure only. It has continuous manual focus but there are click-stops for zone focusing (i.e. near, medium and far). Outside of that, there's nothing much to it. It's about par with my Voigtländer Bessy.
I don't know how many other 126-format cameras Olympus made. This is the first one of which I'm aware.
Picked it up for $3 from a camera thrift shop; another camera with a corroded battery chamber (take your batteries out!!!)