Thank you for your opinion :)
Definitely we needed an experienced designer in our team. But unfortunately we couldn't afford that at first (and probably many in future will face the same situation)
But with the same group of people, we are now moving much faster and with confidence with SQL. And that's my own experience. Just wanted to share that in this article.
I am not saying firebase is bad or anything. Just saying just like everything it has pros and cons. For us, it didn't work. That's all.