Misconception #5: Very limited querying capabilities
Firebase: 5 way-too-common misconceptions
Cathryn Griffiths

Even in your writing, it’s obvious that its actually limited. It’s somehow reasonable that adding kind-of mapping nodes for faster and low data queries but adding a column for multikey queries is certainly limited. Firebase is a great tool for being realtime but most of the misconceptions that you listed are there beacuse of some reasons and having workaround for something would not make anything a misconception.