Would disagree here given that Firebase is the only one of the three owned platform toolkits (Azure, AWS, GCP) that has a really complete first party emulator suite.
But local developer experience is still not good compared to Postgres or Mongo.
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.