I found a project that looks at how machine learning shows up in scientific papers. It covers about 5000 ML related articles from the Nature family of journals and tries to map out trends across countries, institutions, and research areas. Link: https://airesearchtrends.com

Some of the early takeaways are interesting, like how different countries approach ML driven research and how often papers end up being multi org collaborations. Also classical ML still seems to be used a lot more than I expected.