Of all the genres of music, techno and rap/hip-hop require the least amount of talent. But just because they require little talent doesn't make the music bad.
But no form of music requires more overall talent than classical. But to emphasize what KB said, yes...most artists today are overated...but every opinion of music is biased. Some overated artists like Avril Lavigne have good songs, even though they don't give the credit to people who deserve it.
Most of Puff Daddy's songs(P.Diddy) were better back when he was still with Biggie and a year after his death, the music put out by P.Diddy is pretty weak compared to his mid-late 90's stuff.
But one group I always had a fondness for is Bone Thugs N Harmony, too long of a name, but their music was just so addicting. Their R&B-tinged speed rap paved the way for artists like Outkast. Hell, just listen to Notorious Thugs, you might not understand the words if you're not use to their style. Too bad they don't make anymore music.
People like Alanis Morissette, who never had a great voice(but a good voice, nonetheless), can compromise with great lyrics(listen to Ironic) and great overall music(Head Over Feet).
So voice isn't the thing that drives this music industry, it's more the overall talent. Five For Fighting's 100 Years is a great example of using the piano to emphasize the song rather than using voice. John O. doesn't have the greatest voice, but his overall talent is way above average. John Mayer has a great voice for his line of work, which compromises some of his compositions(though not all comps are his work).
But it's just a matter of taste, it's amazing how some songs can stay on the radio forever. It seems like Shaggy's Wasn't Me, it's almost 4 years old and they still play it.