In the Python world, I see this as the microframework (Flask-esque) vs macroframework (Django). I will take Django every single time.

Flask prescribes so little that every project is a snow flake. Which of the N available options will you pick to handle auth/templating/cookies/email/whatever. Real decision fatigue when trying to enable core functionality. Extra special is that many of these libraries are single author creations, so maintenance and security are a mixed bag.

Django - every project roughly looks the same. You get so much out of the box that you must have special requirements if you must supplement with libraries. Since so many bits are first party, you have greater confidence that code is being maintained/checked for security problems.