> Gluing a few libraries together is real software engineering but unless you're really invested in the outcome it's not that engaging and it's not that educational.

That's only true if complex systems don't interest you.

Personally, I have always found the experience of "putting the pieces together" and orchestrating highly diverse systems into a coherent whole to be much more educational than learning about algorithmic details. I also generally find making things work well more interesting than making things work.