Most albums are not "ripped at a very high gain" and they do indeed put out CDs with clipping. Here's some for you to download in FLAC (or rip the CD uncompressed) and check it out, with examples of where some of the worst clipping occurs:

311, Soundsystem (Evolution 0.30)
Aphex Twin, ...I Care Because You Do (Acrid Avid Jam Shred 150.02)
Bjork, Volta (Declare Independence 212.30)
Brian Eno, The Drop (Dutch Blur 102.63)
Chicago Symphony Orchestra, Tschaikowsky: Ouverture 1812 (Ouverture solennelle 1812 op. 49 894.94)
Chumbawamba, Tubthumper (Amnesia 0.01)
Eminem, The Slim Shady LP (My Name Is 20.80)
Fear Factory, Obsolete (Edgecrusher 136.17)
Garbage, Garbage (Queer 249.43)
Green Day, Dookie (Basket Case 41.01)
Iron Maiden, Fear of the Dark (From Here to Eternity 136.01)
John Vanderslice, Cellar Door (Up Above the Sea 203.00)
Linkin Park, Minutes to Midnight (Shadow of the Day 231.59)
Nine Inch Nails, Broken (Last 273.11)
Nine Inch Nails, With Teeth (The Line Begins to Blur 220.42)
Nine Inch Nails, Year Zero (The Warning 127.89)
Nirvana, In Utero (Rape Me 28.15)
R.E.M., Monster (all over Star 69; WTF, Kenneth)
Red Hot Chili Peppers, Californication (Parallel Universe 149.67, Otherside 242.91)
Saul Williams, The Inevitable Rise and Liberation of NiggyTardust! (Convict Colony 195.38)
Smashing Pumpkins The, MACHINA/The Machines of God (The Everlasting Gaze 6.44)
Warren Zevon, Life'll Kill Ya (Porcelain Monkey 203.08)
Various, The Ultimate Demonstration Disc: Chesky Records' Guide to Critical Listening (Johnny Frigo - I Love Paris 263.57, 271.19, 295.86, etc.; track 29, 62.35-62.36, 69.47, and throughout)

It is true that MP3 encoding can also add some level of clipping, but it's unlikely to be significant unless the music is already heavily (dynamic-range) compressed. Anyway, all of the above is based on lossless copies, and the fact that there's clipping on ambient, classical, and stereo test discs should give you an idea how bad the problem is... it also goes back as far as 1992 (NIN's Broken).