Why can't you just do Season 3 on other streaming services when netflix is not working?
You can, the question is why you do not do it.
If the licenses are purchased, you can do that.
Because the rights of the series are Sony. If Sony's terms are just too harsh and no rights and higher share, it is not profitable for a Stramingdienst continue to offer the series. Of course, a streaming service would like to earn some money by offering the works to their customers.