And that's fine that you did.
Leaving and returning did accomplish something. It was just something really bad that then had to be averted. That was literally the crux of the final seasons. And seasons 4 and 5 was mostly rushed due to the writers strike. That derailed a lot of the planning. Again, you still probably wouldn't have gotten your wish of larger island mysteries being explained, they were never going to do that because again as documented it was over their head, and that's more than a valid criticism, but it was still a big factor in the flow of things having to be rushed and certain plot points having to be omitted altogether.