Flask is a Python web framework that provides templates, sessions, static files, debugging and extensions out of the box. However, it encourages patterns that can lead to issues like lack of configuration control, difficulty with composite apps, abuse of templates outside web contexts, reliance on global variables, and lack of asynchronous support. Alternatives include using Flask in a less self-destructive way by avoiding decorators and global variables, or moving to asynchronous frameworks like aiohttp. The key problems are that Flask encourages monolithic apps and global state rather than proper dependency management and configuration.