To me it's reading from different perspectives and other's writing style. It's really important when it comes to political stuff or anything else that you need to base a decision on.
But I think it applies even just to plain articles about a niche you follow.
Like, maybe some new GPU features get released for Linux or something. Gamingonlinux might cover it from a Gaming perspective whereas Phoronix might focus more on the hardware aspect of things and the original blog post or changelog or whatever might just give a mostly a list of changes and a description.
