Of course anyone can look anything up. The point I think the author is making is that the database is better positioned to tell us about potential performance issues. Would be wonderful if we could avoid reading through slow query logs, or paying big money for APM tools, if the db exposed more user friendly information about perf issues or other useful metadata.

The UX of 'damn I have to look that one weird query up again' to look up some metadata is not as good as it could be.