The last time Pakistan appeared composed and in control was during the 2011 World Cup. However, the recent 3 World Cups, including the present one, have been disastrous for Pakistan. In 2015, we somehow managed to win against Ireland, UAE, Zimbabwe, and South Africa, only to be heavily defeated by the Australians in the quarterfinals. I can never forget the beating Wahab received from Russell, and then the 0-4 struggle while batting second.
In the 2019 World Cup, we began the tournament with an all-time low score against the ultra-minnow West Indies side (with Afghanistan and the Netherlands arguably being better than the West Indies). We never managed to recover our run rate and found ourselves in a situation where we were dependent on other teams.
If you observe, there have been two main problems with Pakistan in the last three World Cups. Firstly, the team failed to realize the importance of maintaining a good run rate right from the beginning of the tournament. (Look at how Rohit Sharma has played in this World Cup; his innings are arguably more valuable than Sachin Tendulkar's 600+ runs scored in the 2003 World Cup and Virat Kohli's 49th century.) The second problem lies with the PCB, as they have not managed their ace bowlers well, causing them to be less than fully fit for mega tournaments. In 2015, peak form Junaid Khan got injured, and this year, Naseem also suffered an injury. Both injuries have exposed Pakistan's bowling vulnerabilities on the bigger stage.