Delabole has one primary school and no secondary, so the answer is less about choosing and more about driving. The primary sits in the village and carries its name. The nearest secondary is a car journey, not a walk. Across Cornwall, close to four in five graded schools hold a good or better rating. The schooling here is decent and the logistics are the part you actually have to solve.
Ofsted has graded 120 settings across Cornwall, and 95 of them, close to four in five, are rated good or outstanding. Three carry an outstanding grade. Twenty require improvement and five are rated inadequate. A further 113 settings across the county hold no published grade at all, which means not yet inspected rather than quietly failing, and folding them into the totals would be dishonest arithmetic. These are county-wide numbers covering everything from a two-form village primary to a large secondary at the far end of Cornwall, so they describe the general odds rather than the classroom your child would actually sit in.
Being in the village does not reserve a place at any of them. Cornwall runs its own admissions process, and living near a school gate is an input to that process rather than a guarantee of getting through it. Nobody should buy a house on the assumption that proximity settles the question, and the households who find that out in the spring allocation round are always the ones who never checked.
Delabole Primary School is the one that matters day to day, and it is the reason families with young children can live here without building the week around a commute. The Department for Transport's 2019 modelling puts a primary school at about 7 minutes by car, 9 minutes on foot, and 8 minutes by public transport. Secondary is a different proposition: roughly 15 minutes by car, about 26 by public transport, and close to 69 minutes if you walk it. Those public transport times are the oldest part of that picture and the most likely to have got worse since, because rural bus provision rarely improves quietly. In practice the secondary years here are a driving arrangement or a bus timetable your teenager learns to hate.
Schooling is one of the stronger things Delabole has going for it, provided the child in question is still small. The county's grades are consistently good, the village primary is genuinely local, and the compromise arrives later, when the school day starts with an engine.