In my experience semantic search is great for finding implicit relationships (bad guy => villain) but sometimes fails in unpredictable ways for more elementary matches (friends => friend). That's why it can be good to combine semantic search with something like BM25, which is what I use in my blog search [1]. N-gram text frequency algorithms like TF-IDF and BM25 are also lightning fast compared to semantic search.

[1] https://lukesalamone.github.io/posts/rolling-my-own-blog-sea...