In general, I would split the current volume of basic education into smaller subjects (with many optionals) and finer levels, and have students to make a choice how fast they want to complete them (as long as they would work towards one of these goals).
Sorry to be lazy to not look it up, but I thought it was an interesting take on gamifying learning.
The only thing close in college was profs who would let you test out of classes, and work on a self study project for the class, I loved that.
OK, really, do you want to be stuck with boring and bad textbooks and teachers to drive home the lesson, that some things are just not fun and have to be done anyways?
This can and will be done at home: brushing teeth, bathing, put on clothes, bring out the trash, wash dishes. I have a whole bag of not fun things for my kids to do, that are not fun but have to be done anyways. Turst me, they don't need it in school too. Let learning be fun.