Learn new tech skills with custom-made open-source projects?

Problem: learning new tech skills is best done through practice projects, but those aren't often interesting or realistic.

Idea: take open-source projects that use the desired tech stack, create a custom fork with fill-in-the-blanks, and guide people through fixing up a real-world codebase (and eventually, make their own contributions to open-source). All automatic and based on skill level.

Rough landing page of the idea: https://boilerp.netlify.app

What do you think?