A lot of producers starting using those as cheaper alternatives to hired guns/studio muscians... and there was a control aspect that they had with electronics that they didn't have with studio musicians.
The problem was it became the "sound" by the mid-80s because of overuse...
Then, as dance music became popular, remixes began to feature all of the tricks as a way to extend a 3 min song in 15 minutes (i.e. the remix of "Dancing In The Dark" by Bruce Springsteen):
Speaking of 80s dance remixes there's also an 8+ minute dance remix of Level 42's
Something About You and the dance remix of Chicago's
Along Comes a Woman stretched the song from about 4 minutes to almost 6 minutes.