Getting back to the original question... "Why does all new pop music sound the same?"
ANS: If you restrict your effort to discover new music to boring pop-schlock on playlist radio and the muzak at K-Mart, it does mostly sound alike. Worse, the bean-counters at the big music publishers and distributors have gotten it all down to a dystopian econometric algorithm of hooks and catch phrases. If you listen a bit to promoted hits, most of them lack an actual discernible melody. All they are is a string of hooks and psychometrically-validated snippets strung together to create the illusion of music. Most devolve down to a sing-song cadence not far dissimilar to what 5 year-olds drone on the play-yard. The more mainstream "popular" an artist is, the more and more indistinguishable is each successive "hit" promoted to mass sound (as distinct from music) outlets. It is no longer "music" per se but "product", much the same that the corporate over-class foists upon the consuming public (visions of sheeple grazing at McDarnold's intrude at this point). At another extreme of clone-ish music is most of what is electronically mass-produced for the dance club and rave scene, so dominated by what sounds like a single universal drum machine track. But even here, there are pearls to be discovered.
Fortunately, there is still a surprisingly vast world of new music these past couple decades that has given birth to dozens of new concepts and genres. "Pop" does not even begin to encompass the amazing range and variety of music available to the audiophile of today. I offer the following as a tiny hit of "pop" tunes (broadly speaking) as pudding proof. All are easily find-able on the Net... in no order of preference ...
• Music is My Drug by Techno Squirrels
• Calgary by Bon Iver
• Devastator by Catfish Haven
• Jerk It by Thunderheist
• Breathe by Télépopmusik
• Sonne by Rammstein (Russian-language version recommended)
• Each Time You Fall In Love by Cigarettes After Sex
• Rise by Samantha James (Sade meets Astrud Gilberto meets Basia with perfect diction)
• Look Like That by Sneaks
• I Got It by Marian Hill (Rolling Stone Sperry Session on YouTube)
• Schnitz! by Dorfmeister vs. Madrid De Los Austrias (LoungeMasters Music Video)
• Arabian by gusgus (KEXP Lively Session)
• John Lee Huber (Radio Edit) by TOSCA
• Beautiful Things (DJ Tiesto Mix) by Andain feat. DJ Tiesto
• Hey Now by London Grammar (album vers. & KEXP live session on YouTube)
• Tricky Tricky (Salem's remix) by Röyksopp
• That's Not My Name by The Ting Ting's
• Sirens of the Sea by OceanLab (Above & Beyond)
• Stof by Eefje de Visser (MV on YouTube)
• Crystalfilm (EP version) by Little Dragon
• Crave You: Adventure Club Dubstep Remix by Flight Facilities feat. Giselle
Pop music sounds alike??? Surely this was a rhetorical question.
'Nuff said.