I don't know - I've never thought to myself "I've had enough Tolkien stories represented in film". I'd love to see another representation.
I don't know - that was pretty much my reaction to the Hobbit movies - which were pretty dreadful. I didn't even bother seeing the 3rd one.
Tolkien did, however, create a very detailed and very rich world. There's plenty of backdrop there on which to write new stories whether or not they hew to anything specific that's already been written in that universe. On the other hand, there are plenty of rich worlds that authors have built over time. And most of them don't carry the baggage and weight of expectations that anything associated with Tolkien inevitably would.
ADDED: As noted elsewhere, the rights to other Tolkien works would have to be obtained.
What I meant is I'm not tired of the Tolkien universe and would welcome more. That's not to say I enjoyed the hobbit series whatsoever. For instance, I'd love to see another director try their hand at a Hobbit series on television. At least then I could pretend the Jackson-led Hobbit series didn't exist.
I watched season 1 a lot closer than 2 or 3, but it doesn't seem like they are doing a much world building as they tell each tale.
I don't want to spoil anything but there are multiple characters that exist in both, though obviously younger since season 2 takes place some thirty years before season 1. Some of it is subtle but very interesting once you realize it. I don't want to hint at it more so as not to spoil it.
In effect each season stands alone, you're correct that there's not much world building.