Hello,
Per stats
<https://www.mediawiki.org/wiki/Gerrit/Reports/Changesets_by_project>.
There are 305 open change sets in pywikibot/core which make us the second
project after mediawiki/core in number of open change sets. Open change
sets won't do any harm but sometimes it's hard to find good patches in pool
of out-of-date-or-not-needed-anymore patches.
Some projects have rules like "if a change set has -2 for more than N
weeks, it can be abandoned" it can work for us. Also I think if we look
into our own old patches we might find several patches that are not needed
anymore due to several reasons such as being implemented another way, too
big schema change in pywikibot, etc. We can abandon them. Please check your
old patches.
Best