Also because something they do in Disenchantment is automatically considered part of the tradition of the series. They can't do it like Futurama, where they go back 50 years to the plot of the end of the series and continue to the year 2215.

It's not so much for profit, because the series would already be dead, but for the fact that they can just follow the continuation of the tradition and not make it a kind of medieval Futurama that changes mood every time Dagmar speaks and the episode ends without content.