Jobs can get useful in more complex workflows. The most common use I’ve had for them us running a smoke test suite or a database migration as part of the larger workflow for a big Rails app.
> Jobs do not actually automatically remove themselves from the cluster.
set `ttlSecondsAfterFinished` and they will
> And as far as I know, you can't even reuse the already created Job, so if I want to migrate the database again, I need to make it from scratch.
If you need to run a job on demand, you can always 'kubectl apply -f' the metadata, or you can create a cronjob and `kubectl create job --from` your cronjob. Or, if it needs to run at a particular part of your installation/upgrade workflow, use helm hooks. Jobs are intended to be a one-time thing, so the lack of functionality to repeatedly run them is intentional.