After reading your comment history and searching it, it seems to me that you never learned to use Flask. Jumping into new project and learning a framework at the same time means that you may have to restructure everything after you have learned it.
I learnt it quite well actually. Used it in a few projects one quite large.
It worked ok for internal apis not open to customers, but even then Django was much better as just setting up the admin side provided a lot of value to the business (for free).
All forgotten now but wasted a huge amount of time glueing things together that came for free with Django.
That's my impression at least.