[Fedora-packaging] why the Group tag is obsolete ?

Hi,  A year ago, I learned that Group tag is obsolete [1] I remember ask the reason and is something about comps.xml that I don't remember neither find on google , but for projects that still use repoview, Group tag is needed. So the questions are, have we any replacement for repoview ? or another way to show one repo content ? and why the Group tag is obsolete ? can someone remind me why. And how we now the group of one package ? . Thanks. [1] https://bugzilla.redhat.com/show_bug.cgi?id=1239067#c1 -- Sérgio M. B.