Great ideas, strategies, processes fail to deliver results.
Good ideas are only as good as their implementation. If not done right, you will not reach the desired results, and changes will not stick.
The extreme time pressure forces problems to be solved quickly. Consequently, created solutions are not as effective and robust as they should be. Often they fail to address the root cause, are too 'local' or are conflicting with solutions elsewhere.
Projects are not delivering on their promises, as the entire project environment is not properly prepared (governance, team and/or leadership are lacking).