I don't think that there's much preventing Elasticsearch or Solr from being as fast. Vector search is expensive. Therefore combining the approach with other filtering and querying makes a lot of sense. It's just another tool for search engineers to use. Probably using vector search exclusively would go at the cost of search quality and performance.
Exactly, filtering is vital. That is why Qdrant offers extended filtering, which happens at the same stage as retrieval, not as pre- or post-filtering, with two stages and an impact on performance and quality.
It is not trivial to implement vector search functionality inside a complex framework that is not initially designed for vectors. Besides that, vector search is not only about semantic search.
