In every balanced games which are designed to make fights feel dynamic:
0.5s CC is considered short one.
1s CC is normal.
1.5-2s is a long CC.
2.5s-3s is usually the strongest CC in game and not a single skill in game should exceed that.
Not to mention that nobody likes to stay in CC for 5 seconds. In fight - it feels like forever. You can go make yourself a cup of tea. Also - you either break out of every CC you get - or you end up dead. In majority of cases there is no decision making like "should I break out or handle this little CC to save resources?" Because there are almost no "little CC". If you do not break out - enemy has enough time to kill you 3 times.
Second problem with CC is CC immunity. Every good player runs with CC immunity 24/7. That's why CC, while being generally too long, is considered garbage in PvP (it's just good to have one for non-immune players). Only damage matters.