If a line of code belongs in a project with one file and a main() function, the presumption of impact of that code line on overall code paths is trivial.
If that line of code belongs in a library procedure used by a million LOC project, presumption cannot be done if you don't the project internals and tooling.
Rewriting entire systems or frameworks because one thinks that it's hard to implement a certain class of features is almost always a recipe for disaster.
If a line of code belongs in a project with one file and a main() function, the presumption of impact of that code line on overall code paths is trivial.
If that line of code belongs in a library procedure used by a million LOC project, presumption cannot be done if you don't the project internals and tooling.
Rewriting entire systems or frameworks because one thinks that it's hard to implement a certain class of features is almost always a recipe for disaster.