Firebase Team AMAView other answers to this thread
Is geo-search for Firestore on the roadmap?
Next to full-text-search, geo-search is a requirement A LOT of apps have, and besides the added complexity of using a third party service (such as Algolia), they're also VERY expensive. Also, because of this not being integrated into the suite I've been fighting with race conditions a lot, using transactions to mirror my data from Firestore to Algolia - please do something about that! 🙏
We've answered this in a few other comments (geo queries are popular, who knew?!?) but it's worth answering again.
With Firestore one of the core principles is that query speed depends on the number of results, not the size of the data set. Doing geo queries which are both accurate and fast is really, really hard and we have not yet invested in that. There are some tricks you can do with geohashes though and we're working on getting out some better documentation about that.