if you want or need to optimize for speed, cost, scalability or accuracy.

dedicated solutions have more advanced search features enable more accurate results. search indexing is resource intensive and can contend for resources with postgres/redis. the cost and speed benefits are naturally more pronounced as data volume scales.

for example - chroma has built in regex+trigram search and copy-on-write forking of indexes. this feature combo is killer for the code-search use case.