Criticisms of agile tend to fall into descriptions of cults or religions, based on what I see to be a misapplication of the ideas. This is because I understand agility to be a philosophy, or perhaps an ideology.
Agile is a perspective not a process, although many look to some common 'implementations' of Agile methodologies such as Scrum or SAFE for an off-the-shelf solution. What makes this technique unsuccessful is when:
There is a rigid implementation of process, without the ability or agency to change that process. This is often waterfall in disguise, or Agile in Name Only
There is pressure to stick to the plan, rather than Learn Along the Way.
There is little goal forming other than a vague sense of "complete the work" (Goals tell us the ends not the means) and therefore little to no experimentation and discovery
Fixed deadlines with fixed scope, which do not promote the ability for a team to Work at a sustainable pace
Timeboxes are planned to capacity, not flow
User Stories are treat as hard requirements and not tools for a conversation
This can lead to thinking that "being Agile" is the goal, but it is not. Actually, when considering that Agility is a business capability, Agile processes are better seen as means of competing in a complex and uncertain marketplace, through incorporating learning, experimentation and fast feedback