Judges 2 is another iteration of the theme running through the Bible. God is God.
Man forgets that.
Man requires deliverance from that which he thinks is God. God makes a way. In Joshua 23-24, Joshua warns Israel to serve the Lord, and in Judges 2 Joshua dies. This is disobedience to the command in Deuteronomy 6 to teach children to follow the Lord. This is a challenge that every Christian family should take seriously, especially as our culture becomes more and more post-Christian.