The strategy was to keep them from using all their free time to think about going out in the wilderness to worship.
I agree, Pharaoh wanted the Israelites to forget the God of their fathers and adopt the new gods of Egypt. He did this by making the people very busy and rely on Egyptian slavemasters to keep them fed, that EGYPT was their daily bread. When they came out, the Moses later said:
"So He humbled you, allowing you to hunger and fed you manna which you did not know, nor did your fathers know, that He might make you know that man shall not live by bread alone, but man lives by every word that proceeds from the mouth of the LORD." Deuteronomy 8:3