Until recently, parents in Thailand would leave their children in Buddhist temples while they worked the fields and factories. Buddhist monks would act as caretakers and teachers. Religious education was strong, as were the donations flooding into Buddhist temples. But with the rise of state-run primary school education, religious education has slipped dramatically (so too the temples' cash flow).
This is a familiar story across Southeast Asia. As the region climbs from the bottom rung of the economic ladder, there is often less time devoted to religious practice and more to working the fields or putting in hours at the office.