Longer anime tend to lose their edge with time. The o ly one I still enjoy is One Piece.
You're the second person to tell me this recently. I'm kind of curious what makes them lose their edge. Do the stories just meander and drag on or does the storytelling get more sloppy? Or do you just kind of lose interest in the characters?
While I don't know if it's technically anime, Netflix's Voltron series was pretty frustrating to watch. As the series dragged on, plot points were often abandoned or rushed to be resolved, character development was often any combination of forced and unnatural, abrupt, or non-sensical. On and on I could go. In general, it felt like starting out the writers had a clear vision for where they wanted the story to go, but by season three, they were starting to say "Eh, whatever. We guess these ideas will work."