It seems like more and more services are being moved under the Firebase umbrella (Crashlytics for example), signalling Google is committed long term to Firebase. It is a considerable form of cloud lock-in if you get your data into Firebase (firestore) and a competitive advantage over AWS, so there is good reason to believe this is long term strategy as well.

> My biggest concern with Firebase is if it's still going to be around in a year or two

That's interesting , why Firebase would go away ?

It's just back end on top of GCloud.

Actually , everytime you do something in Firebase , it create a ressources in your GCloud account.

Firebase may not be super popular for SaaS but for Mobile , it's the king and by far , you can use it with no doubt.

I think most of the concern comes from Google shutting down services and apis pretty regularly. I wouldn't use it for large projects or long term projects because of how differently you need to write things to effectively work with it.