I don't actually like Flask. Sure it's lightweight, but it's only light because it doesn't do much of anything without help. Setup & configuration is necessarily messy and the documentation actually encourages some questionable design patterns.

I only used it in this project because I was 100% confident that the web service in question was only ever going to need to do one thing and one thing only. It's also convenient that i could just do a apk add python3-flask without having to worry about using pip to manage packages.