So for the sake of completion, I marathoned the lowest rated TV series in the Digimon franchise - "Xros Wars: The Young Hunters who Leapt through Time", the sequel to 2010's "Digimon: Xros Wars".
Despite the title, the Hunters do not time travel at all sadly. But nevertheless, despite being the so-called "worst entry" it wasn't too bad. Maybe I've just got used to seeing garbage anime that a "meh" series like Hunters looks good in comparison. It was certainly a massive step down from the original "Xros Wars" and even could be argued to be an unnecessary sequel since 90% of the show is just "Monster of the Week" that doesn't lead anywhere. When the plot finally kicks in during the last four episodes, it's about a bland generic doomsday monster that wants to destroy the world yada yada yada. Even the hero was nothing more than a static shonen hero who had a personality as deep as a puddle. There were some genuinely good moments, mostly whenever the plot focused on a returning character from the original show.
All in all, I can definitely see why it's called the worst, but I don't have quite the hate I've seen others throw at this show. Mostly I see it as a forgettable sequel that had some good ideas but flopped on the execution.