For another set of measurements that support RRF + Hybrid > vectors, we (Azure AI Search team) did a bunch of evaluations a few months ago: https://techcommunity.microsoft.com/t5/ai-azure-ai-services-...

We also included supporting data in that write up showing you can improve significantly on top of Hybrid/RRF using a reranking stage (assuming you have a good reranker model), so we shipped one as an optional step as part of our search engine.