I'm going to talk about the backend, since lots of people are talking about frontend. "Framework" covers a lot of ground. It ranges from Flask, which is basically a request router, and in languages like Go is part of the standard library, to Ruby on Rails or Django which provide logins and sessions, an ORM, and piles of other stuff.
Most backends are wrappers around a relational database. You save time by
2 and 3 aren't really framework material, though libraries to do them may be included in frameworks. So when should you use a backend framework? If you can find a framework that provides a big hunk of your business logic that you then don't have to write yourself without messing up your ability to write the endpoints you need otherwise.
We're a place where coders share, stay up-to-date and grow their careers.
We strive for transparency and don't collect excess data.