The point is that the Egyptians had become ignorant secularists who deny God at every chance they get just like Americans do now. Pharoah was an analog to this like Trump is to us (nah don't come to me with this "he's a Christian bull." God is an ideal. You don't get saved by saying a few words like Pentecostals believe). And in the Bible, the plagues were ended but Pharoah threatened to kill Moses if he showed his face again. Imagine the gall it would take to make this threat. Moses acquiesced, but God stops and tells him to stand his ground. It's then that the final plague is summoned. It didn't have to come to this. Mind the greater context here. Israelites owned not only all the cattle but the entire country except for priests' lands when the Egyptians had to mortgage their lands for wheat during the 14 year drought. That was only a few generations before. They returned the land and then Jacob died, and then the Pharoahs who were friends with the Israelites died. So the new Egyptians got cocky and started to abuse those who they owed so much to. Why do you think the Egyptians all ran out and showered the Israelites with gold and trinkets? It took the Pharoah's waking up to wake them up.