Obviously other than skill & the inclusion of guitar instrumentals, I wonder if the instrumental guitar solo died because of radio play.

Presumably there was a push to have radio edits of popular songs be shorter to run more ads, have more inane DJ bumpers & morning zoo bs, squeeze in more of the Top 40 repeats to fulfill contractual obligations for exposure, etc.

The lyricless instrumental solos are surely one of the first victims when trying to truncate radio edits for the most popular songs when everything in corporate radio gets min/maxed.