The descent of the Israelites in Egypt from welcome guests to oppressed slaves was a gradual and systematic decline. The primary approach among commentators is that the Egyptians acted with outright cruelty toward the Israelites [מלבי״ם, רש״ר הירש, ביאור יש״ר, ביאור שטיינזלץ]. This behavior was rooted in deep ingratitude. The Egyptians forgot the salvation Joseph had brought them during the years of famine, choosing instead to repay good with evil [ביאור יש״ר]. While the Israelites were initially treated well, jealousy eventually poisoned the Egyptians' attitude. This envy drove them to scheme and issue harsh decrees designed to break the Israelites' strength and reduce their growing numbers [מלבי״ם, רש״ר הירש, בכור שור]. Offering a completely different perspective, another approach suggests that the Egyptians did not just act cruelly, but actively painted the Israelites as evil. They fabricated accusations, framing the Israelites as ungrateful traitors who might join Egypt's enemies, a thought that had never even crossed the Israelites' minds [העמק דבר].
The next phase of their downfall was the complete loss of freedom. The Israelites were stripped of their status as free residents and reduced to slaves, a vulnerability that stemmed from living as strangers in a foreign land [רש״ר הירש, ביאור יש״ר]. The exact nature of this suffering is debated. One view suggests the affliction came from imposing burdens and tasks that the Israelites were entirely unaccustomed to, since forcing a person into unfamiliar work is a form of torment in itself [מלבי״ם]. Conversely, another perspective argues that the suffering came from pointless labor. This work was not designed to benefit the Egyptian masters, but solely to crush the spirit of the workers, such as forcing men and women to switch their traditional roles [העמק דבר].
Once the Israelites grew accustomed to these initial burdens, the Egyptians escalated their cruelty by imposing objectively exhausting and backbreaking labor. They forced the Israelites into intense physical work with mortar, bricks, and fieldwork, tasks that are grueling even for those who are used to heavy manual labor [מלבי״ם, העמק דבר, ביאור יש״ר].
This reality of absolute enslavement completely stripped the Israelites of their independent legal standing. Because everything a slave acquires automatically belongs to his master, the Israelites were legally unfit to receive the Promised Land as a gift from God while still under the yoke of slavery. They had to be liberated and forged into a free nation before they could rightfully inherit it [ספורנו].