Is my recollection mostly correct that there were few, or essentially no
consumer market 8-track decks that permitted people to record their own
8-track compilations for use in the car (or elsewhere)?
When acquaintances remarked to me in the 1990s that they did not see
the cassette being displaced entirely by the CD, my response was that
the introduction of a recordable CD would be the end of the cassette
once the economics became comparable to cassette feedstock and
technology.
Similarly, is it correct to surmise that the ability (eventually) to
make reasonably decent recordings of one's own LPs to cassette, or
custom compilations, was the major reason for the format's disappearance
in the early 1970s?
(The 8-track format had a number of things going against it, and would
have passed from the scene at some point. The question here is why did
it disappear when it did.)