I'm beginning to think this is something Coldplay was very conscious of while making this album. It's no secret that the simplicity of pop songs leads to artists using similar(or identical) chord structures for different songs. I'm sure that Coldplay recognized this pattern in their song writing, and decided to embrace it 100%. Rather than try and write stuff radically different than what comes natural to them, they just gave into this specific catchy hook and decided build the whole album around it. There's obviously a ton of production on this new album, and I think that really helps differentiate each track from one another. The songs are arranged and recorded so well, that it took us this long to recognize how similar they are. Between the different melodies, lyrics, instrumentation, and production, each song seems to stand out quite well on its own. Personally, I think it's quite impressive how dynamic and epic this album is despite the repetition of such simple song structures. Although, that's probably why I've liked Coldplay all along.