John Wesley on 2 Kings 21:9

More evil - Partly, because they were not contented with those idols which the Canaanites worshipped, but either invented, or borrowed from other nations many new idols, and partly, because as their light was far more clear, their obligations to God infinitely higher, and their helps against idolatry much stronger than the Canaanites had; so their sins, though the same in kind, were unspeakably worse in respect of these dreadful aggravations.