What percentage of the population are in K-12 any given time -- 15%? 20%? To have 1-1 tuition for all of them, we'd have to have at least that many adults also in education.
In the US it's ~10% of the population. Completely doable, especially since the participation rate in the economy is still lower than at any point in the last 50 years (minus covid). If that seems to hard I guess we can increase class sizes by 100% and have 2 on 1 education.