Another upvote for ScaNN. Used on Teclis.com search engine in production (replaced previously used Faiss, which was excellent). ScaNN is almost double the performance and with same 5 lines of code to implement locally.

At this point vector search is almost 'solved', the challenge remains the quality of vectors fed into the index. Producing accurate text/image/... vector representations (aka embeddings) is where lot more progress needs to be made.