I recall the Remington Accelerator ammo of the late 1970's and found it kind of a fascinating concept. But then it seemed to vanish as quickly as it appeared. Never heard an official reason for that but all the unofficial scuttlebutt I heard was, "It didn't sell" and left me wondering if poor sales were due to guys hesitant to try new stuff, or else the stuff didn't perform and the word got around in those pre-internet days that it was crap.
I heard (but never experienced) that accuracy declined after the initial few years after introduction.
But I suspect the big reason for discontinuing the Accelerators was most hunters buying more specialized rifles for every purpose, along with the increase in handloading. In the 1950s and into the early 1960s, many cartridges were introduced as multi-purpose, such as the .243 Winchester. The sales pitch back then is that you could use the same cartridge/rifle on everything from prairie dogs to deer--which would make buying a new rifle more friendly to the family budget. (And thus pleasing the "little woman.).
But as the American economy kept growing, more shooters started buying a specialized rifle for various purposes. Exactly like the rifle loonies who inhabit this site....