Every single NHL team goes through a rebuilding process, especially since the salary cap was introduced as a result of the 2004-05 lockout. It’s exactly how the cap, and the draft for that matter, is intended to work: the good teams pay (and oftentimes overpay) their star players during their window of contention in order to keep the group together during their primes. They give up good future assets like high draft picks and promising prospects for “win-now” pieces that can help them immediately.
Then, these prime players hit the aging curve and start declining while still being paid handsomely.