Here is how it used to work: folks would watch MTV. MTV played music videos. The music videos gave you light entertainment and some eye candy. (Sometimes they were truly inspiring works of art.) In return for that you would listen to the music. If you liked it, you went out and bought a CD. The folks who paid for the music video made a handsome profit and everyone was happy.
In other words, music videos were essentially TV ads for music.
So why has real music video production mostly disappeared? The problem is that the record industry has declined precipitously. They no longer make real money from music, and there is therefore no reason (or desire, or the requisite money) to produce music videos. It’s a dead industry.
This is a terrible shame, because music videos used to be an excellent way for new directors to break into the industry. It still wasn’t easy to make the jump to TV commercials or features, but it was a viable way to earn a living as a director. Music videos can still have reel (as opposed to real) value, if you can find someone who is willing to pay the production costs.
These days music videos are mostly made at a loss, like vanity projects, in the hope that they will be watched on YouTube. That’s great – singers are understandably keen to appear in music videos. The problem is that the old model was profitable because you tuned into MTV and had to watch whatever music videos they put on the playlist. In other words, it was an unsolicited sales pitch, just like TV commercials. Conversely, if you put a music video on YouTube, most people who watch it were looking for that specific artist, so it is unlikely that the video will generate net growth of the fan base.
The record industry did not stop producing value, but the Internet short-circuited their business model and wiped out their profits. Hence music video directors are left out on the street, their services sadly no longer required.