New Mexico went from 17% population with a 4-year college degree in 2000 (first cohort under scholarship system) to 27% today. Still not enough to make it “commonplace” but clearly efficient in raising the population’s skills.
Further, the fact students who need remedial classes are encouraged to take them right away would have a powerful effect in ensuring students do keep up.
Nowadays, businesses look at workforce qualification as a primary criterion (vocational, two-year, or, especially, 4-year college graduates) + most jobs which pay decently require a degree and thus have good ROI, which is why Tennessee Promise was implemented. It’s just a good investment for growth.