Reasonable points all. A couple of friendly responses:
-Inaturalist added something like 400,000 new users over 2023. Is it a bad idea to try to increase the number of users by more than that in 2024?
-The technical issues you mention are very real. The logical next step seems like it should be to fix the technical issues in order to accommodate more growth, not to limit growth in order to keep the technical problems under control.
-The rhetoric of exponential growth has been abused by business people. Environmentalists should reclaim it by promoting exponential growth in environmental consciousness, scientific research, and populations of endangered organisms.
-But as you say, growth isn’t everything. Data quality also matters.