The pagan gods were not jealous. They tolerated and even encouraged their worshipers to adore many other gods. Not so with the Lord. He wanted to be the exclusive God of His people and could not tolerate seeing them worshiping Him and other gods. In today's Western society people do not worship idols in the narrow sense of the word.
Modern idolatry is more abstract and difficult to identify.
Please allow me a homiletical detour. If our search for inner peace and joy leads us to ignore the Word of God, if our search for financial security leads us to violate God's will and to oppress or ignore the needy, if the search for self-fulfillment has crowded out the time we used to spend with the Lord, then we have an idol. The problem with idolatry was and continues to be related to our anxious concern for personal, economic, social, and psychological security.