That feels like it's more a function of the lack of a query UI whereas Pg and Mongo have a lot of options.

I used Firefoo for a while and Google should just buy that product and ship it with Firebase. Otherwise, I have no issues with local Firestore emulation; everything works as I expected it with a few edge cases.

Have you ever come across Fuego or had a chance to try it? It supports complex Firestore queries, including Firestore Enterprise pipeline queries and Point-in-Time Recovery (PITR).