Few words.
Starting from fatigue, our players have been through a lot of stress with continuous cricket in the past few months. But these are professionals, we expect them to have a good run without proper rest which seems idiotic but we have done that and have been doing it.
Secondly, team selection and management. Yes, the selectors picked the best possible squad. And I liked the way they reasoned out for picking certain players. Having said that, it was the duty of the selection committee to review their selection by the end of IPL to determine if the picks they made are doing well as expected. They missed the trick to include Chahal. He did have a bad phase recently, but he did well in the second half of IPL. And most importantly he is a wicket taking bowler. Hardik Pandya too is not a wise choice. Bhuvi was not at all impactful in IPL. Shastri, Kohli and Dhoni have the authority to make the above calls and make sure they put up the best squad they could. But I don't think they did, because they went ahead euth experience rather than backing new players.
Players looked clueless, lacked confidence and motivation. Did we miss the trick to send the players with best form currently in recently concluded IPL? No. Varun Chakravarty, Rahul, Shami etc.. did great in IPL, but failed in WC. So we can't say that we sent a worst and out of form squad to WC.
It's best to sit down, draw a roadmap, formulate new strategies and tactics, scout the best from the domestic circuit and irrespective of their international matches experience, back them. Kohli won't be there as captain by the end of this tournament. Shastri will be gone, so it's best to have Dravid pick his team rather than him given a team to start off with.