Hybrid might work for English but where are you going to get sparse embeddings like SPLADE or ELSERv2 for most other languages? Vector search with ada-002 or text-003-large capped to the first 500-1000 dimensions will give you a support for 100+ languages for free. If you are using BM25, then you need to train BM25 on every single separate knowledge base which is annoying and expensive.