Scan for exploits, spyware and viruses, actually automatically format the PRs if they don't match and warn the submitter, automatically upmerge main/master into branches under consideration where possible and ensure all new functionality has test cases (not the same as code coverage).

When if comes to the human reviewer unless an issue is structural, don't care so much about the formatting and keep to one human approval. For simple changes, like documentation, comments etc, these can be approved by bots themselves as any fault is non functional.

If you consider that if bugs are noticed they will be fixed by other PRs, it makes less sense now to try to fix all issues in each PR, especially as there's no guarantee this would cover all of them anyway with so many ongoing changes.

I'm not saying 1.7K a week, but they aren't keeping on top of the PRs being raised so the number just keeps increasing, unless bots just close them because of inactivity.

At some point they will have to cut their losses, strip back to a week's worth of PRs and close everything else to get back on top (perhaps this is actually what is happening, it just takes the bots a while to chug through them).

Edit: just checked and it's now 1.9K PRs.