Alternatives to ChromaDB for easy RAG search

I'm disappointed that ChromaDB's local, free "single node" version is still getting second-class, hand-me-down features while the "distributed" version (a SaaS offering, unsurprisingly) gets built in hybrid search, BM25, etc. I tried to give the benefit of the doubt and wait, but half a year later there's not even an announcement or discussion of feature parity on the roadmap.

What are some truly open source, on-premises alternatives well suited to semantically searching and re-ranking large collections of long (200+ page) documents? Exact string matches, semantic matches, and direct retrieval by page number (or ULID) would be required.