Like what you like and all, there's decent modern pop, the same the there was absolute tripe pop back in the 60s and 70s. However...iInvalid Link Removed
Now, that's a point I appreciate. Simplicity and homogeneity can be defined and measured. They don't necessarily make music "worse," though they can. The assumption of the first part of the OP's video assumes it does. But simple music can also be powerful.
The other problem is that the frame of reference is misleading. When one frames it as "Beatles to Bieber," you're using an outlier as your starting benchmark rather than a standard. The Beatles were popular, of course - but they were extraordinary. That was the whole point. One can't use them as a starting point of reference. It's rather like talking about the economy using the 50s as the starting point; that wasn't when the economy was "normal," that's when it was in an extraordinary boom that was due to unique circumstances that hadn't existed before or since.
And finally, like I posted earlier, the video relies on "chart-topping music" as though it's apples to apples, as though the top 40 charts today are the direct equivalent in the music world of the top 40 charts of 50 years ago. As I said, they aren't. I was struck by a Chris Squire interview, before he died, where he was talking about how there was so much less music available then than there is today. So the video can assert that they studied half a million songs from the 50s to today, but not point out that so many more songs are released now than in the 50s; the top 40 are a different proportion of the market, and the market itself is entirely different in how music is produced and acquired and experienced.
When the guy in the video does weave that into his argument, he winds up contradicting himself. He argues that back in the day of vinyl LPs and no iPods, you bought an album, took it home, and listened to it over and over until you absorbed all its nuances and came to love it, and that made music better. Later on he argues that part of modern pop's inferiority is in familiarity, that it's bad that people like hearing something they've listened to over and over. So what supposedly made older music great now makes modern music bad?
He's also incredibly naïve about the operating of the classic music industry, as though it were all producers looking for talent and only talent, and as though the public were buying music based on a nuanced appreciation of their genius. That's laughable. And again he contradicts himself, admitting in passing that older record execs would "throw a few thousand pounds" at promoting an artist but then blaming the modern industry for "brainwashing" people into liking bad music by repeated exposure. Payola, anyone?
It's true that modern record execs are more risk-averse than they used to be. But he ignores that it isn't just that artists cost more to promote. It's also that in the age of file-sharing, there's less money to be made if the artist hits it big anyway. The top 40 as a market share has shrunk. People find their music by other means. Creativity isn't "dying" -- it's bypassing the record companies.