The salary cap is a hindrance, but if you spend the money on the right players then you can field a competitive team year after year. Look where the perennial contenders invest their money. They retain the core pieces and build around it with cheaper FA's, role players, and a steady cycle of other home grown pieces.
Say what you want about the Pens and their tanking, but Ray Shero has done a spectacular job of building that team to be competitive year after year. He has fantastic supporting players and keeps the talent pool stocked in the right places. He also spends the money he has in the proper areas.
Each year we field a team full of mercenaries, spend the year wondering what's going wrong, and then scrap it and build a new squad on July 1st.