GBIF has a forum (also using Discourse, so it should feel familiar!) and I thought people might be interested in this post GBIF activity reports updated for 2019.
I just glanced at a couple of countries to get a sense of their data overall and how much of the GBIF data from that country is from iNaturalist, e.g.
Russia
Australia
United States of America
Lots of cool graphs in these country summaries.