At its peak I had to shepherd ~50 masters of varying ages, plugins and levels of customisations.
Yes, it allowed repeatable builds, and it can be, in certain circumstances a very good replacement for cron jobs where you need to administer >5000 machines.
However, it has an offensive UI, the plugin system appears to be designed to deliberately cause things to break, versioning the flows is difficult, unless you rely on plugins (which break) or want to learn groovy.
Automating and making jenkins it's self repeatable is a soul sapping task.
In short, jenkins needs to disappear.
Yes, cirle is crap, bamboo suck massive genitals.
However I have had great success with gitlab runners. Now that gitlab is actually reliable, they are a brilliant first class integration into a git workflow.