cat output/usage-by-api.json| jq -r '.' | grep -v '\[' | grep -v '\]' | sed 's/[ ",]//g' | sort -u
So, nothing terribly outstanding when comparing to https://issues.jenkins-ci.org/browse/JENKINS-51965?focusedCommentId=357813&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-357813
A few differences, but mostly the same. I assume partly because some plugins are actually hosted elsewhere. A bit surprised I didn't find fitnesse before, but well it's another case of DatatypeConverter.
I am going to close this, and link it to JENKINS-55944, so it can help there. The goal here was mostly to check we didn't miss a lot of plugins from previous analysis, and/or some that would be installed like 100k times and we didn't check they specific case.