Yes, it has gotten beter over time, and this is why-
The show is taking current news and making comedic plots out of it. In that sense, the show can never run out of ideas because the world is changing everyday. The show analyzes trends, events, and media, and does a great job of doing so.
BTW, my favorite South Park is when Cartman was planning revenge on some older kid because the kid wheedled Cartman into buying pubic hair. Without going into details, that show was
, especially at the end when Cartman exacted his revenge after many failed attempts at redemption.