A few years ago I became addicted to a British show called The Detectorists. It was a show deeper than the surface topic (as is Shtisel) and when the show ended after season 2, I felt empty.
Then it was picked up for a third season under different management and I waited eagerly. Unfortunately, that season was crap. I wish they hadn’t made it.
I guess what I’m trying to say is be cautiously optimistic about third seasons.