How to contribute? Dead PRs?

[Zaczero]

Description

I am struggling to understand why some many PRs are left unmerged.

#9483
#9482
#9454
#9424
#9315
…
to name a few.

So many features and fixes are waiting... for what exactly?

I did read https://github.com/openstreetmap/iD/blob/develop/CONTRIBUTING.md but it did not answer any of my questions.

I really want to contribute to iD but this is a massive blocker for me.
I do not want to waste my time just to have a dead PR.

Please help my understand what's the procedure for having a PR merged.

Screenshots

No response