It got dropped by Syfy after three seasons and picked up again by Amazon for a further three seasons. Bezos was apparently a fan. They didn’t renew it after that, but it ended in a decent place, closing out a lot of the plot lines while leaving the door open for more. There’s some stuff setting up future plot threads that they don’t get to address, but it mostly won’t leave you hanging. It’s well worth finishing.

I won’t spoil anything, but adapting the final trilogy would involve some difficult changes and be very expensive, so I suppose it’s understandable that they didn’t keep it going, as much as that sucks. Maybe one day. There’s comics and a Telltale game coming out, so there’s still life in it yet. And you can always read the books.