Since my recent decision to become an indie maker, I have got my hands dirty with possibly every stack available and concluded upon Flutter + Firebase. I can complete 99% of my planned projects with it. And I am astounded. It is too good to be true and I sure I am missing out something. Can some one explain what am I missing?

For context, I've been into Data Science for more that 9 years now, professionally. And the tech stack my DS works and deployment demands is mostly different than a full stack's. So I could be missing out something very silly.