Days Gone does nothing particularly bad - in fact, I like many of the game's ideas very well, and a handful of the characters you get acquainted with are quite exciting - but unfortunately, much of that game makes so painfully mediocre and little elegant that it's impossible to overlook it.
What can initially seem like a refreshing and high-budget twist on classic survival games, turns out to be a rather traditional and sometimes very uninspired variety of much better games. Mad Max tackles post-apocalypse, cults and battles for life and death better, Dying Light has better zombies, and it's not exactly lacking in bottom-solid open world games these days.
By comparison, Days Gone is a completely fun game. It has, as I said, many good ideas, exciting progression, a bunch of wonderfully realized characters and a story that is capable of engaging heavily during periods, but the experience is far too long for its own good and the whole is simply not polished enough.