Older anime had more Episodes/Seasons and Complete adaptations.

BurningSpirit said:
It's clear that long running series are only those that guarantee long term profits. Anime are also increasingly being adapted from unfinished source material.

I would like to put out the fact that the newer format has it's flaws, but also has it's merits. Often as we see in long running anime, they often catch up with the source material, so it's either hiatus, filler or horribly slow pacing (all of which ruin the show). Having shorter anime prevents this, but often when trying to fit into 12 or 24 episodes, they get dragged out or rushed slightly.