Most of the sermons I’ve heard don’t focus on the Pharisees or listeners at all, but aspects of the two sons.
Same here, but it's an awful long Gospel reading so it's understandable that a homilist will have to leave a lot of details unsaid to focus on other things. That's why it's important that Catholics prepare themselves for the mass readings ahead of time by being good students and pray-ers of the Bible. The Bible study group I lead does exactly that and people tell me it is transformative for how they understand the readings each week.