When does it make sense to *not* use Redis for caching? Like, when is it just too much?

weve been using redis for our primary caching layer for a few years now, and its been fantastic. it handles our load well and offers a lot of flexibility. but, im starting to wonder if for some of our simpler services, its becoming overkill. are there situations where a simpler in-memory cache or even just basic database indexing might be sufficient and less complex to manage. curious to hear about your experiences and decision points for choosing a caching solution