Yes that's right. We didn't have the skill and didn't have the experience. And obviously I am not saying that firebase is total garbage. Obviously firebase has some great features and that can help lots of newcomers like us.
But in the long run I think firebase is a wrong choice for complex application.
I don't know how would an expert architect help us to make complex queries in firebase because that's not what firebase is intended for.
And also there must be a reason why we don't often see very large companies that use firebase.
Thank you for your opinion :)