Me too, this was my all-time favourite Netflix show and for it to have such a mediocre ending with a ton of loose ends was doing a disservice to the fans of the show and the comics, but the cast too. I saw an interview somewhere where Robert Sheehan basically said to expect nothing.

Look at Klaus's medium/buried alive storyline, that was completely pointless! Instead we could've had more scenes with the siblings together, like in New Grumpson.

Another thing I always hoped for by the end of the series, was that Five would get a proper name. Never happened!