For those who grew up buying records, part of the fascination was not just listening, but reading. The inner sleeve of records often had extensive notes, lyrics and credits for everything from the songwriter to the cover art designer. Before the days of streaming and the internet, this was often how music information was discovered. If you liked a producer or a guitar player on a record, you would find out who it was from the liner notes and look for that person's work elsewhere.
This was particularly important for musicians. Credits on albums and songs are like credits for actors, except musicians don't have an IMDB.
In fact, since streaming essentially swallowed whole the music world, liner notes have all but disappeared. Spotfiy, Apple Music, Tidal and others will display limited cred