That's a reasonable response to so many open PRs but it's not a great situation to get used to as it means less consensus and velocity.
If a PR is merged, that doesn't mean the NIP is final. It just means `main` is open for follow-on PRs from others. In the current state, there's a lot more energy spent on discussion without resolution than improved NIPs.
Bias toward merging and interested parties will know they can correct things quickly. As it is, half the time I go looking for a NIP it's not even in the README so I must search which is a waste when multiplied by n contributors.
I can't argue with all the great work that's been done so far but I see a lot more potential to be unlocked.