We have other tools that are self hosted and they require regular maintenance to security patch, write storage retention policies when some stupid log fills up, have backups, migrate cloud images, stop using plugin with deprecated api, etc. This stuff can also be unplanned and even scheduled becomes a regular chore taking time away from customers.
I know the on-prem sharks smell blood in the water but on-prem is not all upside and not the default answer to hosted services having downtime.
For example we could be on another DevOps SaaS and have zero downtime in March.