The longbox was the original standardized packaging format for CDs, but since the longbox itself was disposable -- the actual CD was stored in a plastic "jewel case" inside, you were supposed to keep the plastic case and throw away the longbox -- there was an outcry against them as wasteful packaging. (See for instance this article, from 1990: https://ew.com/article/1990/04/20/whats-cd-longbox/)
The recording industry loved the longbox, because it supposedly made CDs harder to shoplift. But for an industry that generally likes to consider itself progressive, being the target of protests by environmentalists was a bad look. So by the early '90s they'd given up on the longbox, dropping it completely and just shipping the CD in the plastic "jewel case" by itself.
The longbox CD package format meant that retailers could use their existing LP storage bins to sell CDs as well during the transition period. The CD jewel case was visible above the shelves below it.
As retailers installed dedicated CD shelving systems, the longbox format was abandoned.
The recording industry loved the longbox, because it supposedly made CDs harder to shoplift. But for an industry that generally likes to consider itself progressive, being the target of protests by environmentalists was a bad look. So by the early '90s they'd given up on the longbox, dropping it completely and just shipping the CD in the plastic "jewel case" by itself.