Perhaps the fatalism of the godly king Hezekiah in the last chapter was because he already knew his son would be a disaster.
Manasseh became king at a young age and re established the pantheon of folk Gods, sacrificed his son to Moloch, set up Ashera actually in the temple, consulted wizards and mediums and shed much innocent blood to boot.
There is argument over whether these gods are Canaanite or folk Gods of Israel itself. I guess the calf at least, which they worshipped in the desert came from some folk tradition. Abraham came from a household with Gods.
The sacrificial system is just an adaptation of the religion that was already there to monotheistic worship of jahweh. God is about substance and we’ve seen faith in him come in many forms. He meets our understanding where it is.
His son rules 2 years and is much the same.
Bad Kings are accompanied by more and more pointed prophetic reaction, this time God says he will wipe Jerusalem clean.