I'm not arguing against using a framework, if it fits your project requirements, and we can argue the day long about micro-vs-full-stack. There are good arguments for both, they suit different people and projects.

My own observation is that bad codebases are the result of bad development practices regardless of framework. In my last job the code quality was so poor (and the management processes so broken) that whether they'd used Django, Flask or roll-your-own would not have made a whit of difference.