alot of shows started doing this, and then the actors got too old(ISAIP,spn) and everyone forgot about the series, and then quality went down as well too.

and not as bad as orville, 6 years for 3 seasons, and 4th season may not even materialize, because its always in a limbo. one of the leads of orville(the palacki in rosenbaums podcast) said it was insane and too unaffordable to wait that long per season.

and then the fabled AOT which was almost 10years for 4seasons.