[initdaemon]

You didn't include the maintenance cost to manage your infrastructure and container platform, which you don't need to worry with a hosted service.

[byroot]

Even with those it was still worth it. A couple people maintaining the CI is nothing if you can make the build of the 350 other developers twice as fast.

Also it's not like hosted CI is without maintenance, if you want it to not be totally sluggish, you have to use some quite complex scripts and caching strategies that need to be maintained.