It's not as bad as you think, I run the helm upgrade when patches come out, the backing store is S3 or managed SQL, it runs a nightly k8s cron called gitlab-backup which tarballs the whole thing into an s3 bucket with a single command restore should disaster strike. (This is part of the product, not a thing I wrote.)

I probably only babysit it for 30 minutes per year, including all the upgrades.

It depends how high you value your headaches, and how high, your org's downtime. Github not working accrues over the hourly rate of every developer affected, which is likely $70-$100 a hour. 10 hours of outage in a year affecting a team of 10 would cost north of $70k, enough to hire a part-time SRE dedicated just to tend to your Gitlab installation.

^ this. the last thing i want is to add to my workload. take my money and make my life easier, even if it means that for one hour every couple months i can't do anything