Earlier quoted context omitted.
Since your Looker setup is well-maintained, did you consider adopting the data catalog in Looker, what would be the challenge doing it?
The main reason is that only a subset of all our datasets are actually exposed in Looker, and Amundsen would have applicability to other data sources - certain production semi-OLAP DBs, the future hive-on-S3 deployment... that we have no plans to expose in Looker at all. That said I haven't looked closely at how far we could go with Looker, I'll check it out.
I would love to hear the features that you would need in a data catalog system.