Why does all new pop music sound the same?

Because in order to be popular these days it has to be generic enough to appeal to more diverse kinds of people in a vary basic way than ever. Much like fast food.

Better off forgetting about what is popular or promoted heavily and find your own good music. There is more of that out there than ever these days and growing. Its all up to you not others to find the music you like. The tools and material to do it is all out there. Some of it might even turn out to be or have been popular.

Don’t be afraid to go way back if needed. Great music was made and recorded as far back as the first 3rd of the 20th century and digital remastering and streaming works wonders. Way before The Beatles hit. Go figure!

I always thought the similarity to Pop music nowadays is because they share the same writers, and producers. If you have a producer who works with a pop starlet and they make tons of money then the record label will use that same producer for other pop stars till the world gets tired of the producer's schtick.

Look at the artists who top the Billboard charts and tell me they are not part of a manufacturing process by the same hit factories.

Motown is a great example of a hit factory, and there have been others. I'm saying in the past there was more diversity on the Billboard charts. And I'm someone who was always seeking an alternative. 

I do agree that this is their time in music and pop culture, just as I had my day. But I'm not pining for it, I've moved on.

As the article stated, it's 1 or 2% making 80% of the pop music today.