The CELTA is intensive, which I think defies logic. Teacher trainees are being taught how to teach English with a coursebook (workbook). I believe that CELTA tutors make it intensive, to create the illusion that the trainees accomplished more than a test of endurance. 

The course is usually taught over four weeks so that the trainees are so busy that they do not have time to question what is going on. The CELTA is a pass /fail certification without criteria or a textbook. It was my experience that the lack of criteria enabled my tutors to play mind games and go on power trips. I observed the tutors constantly moving the 

goalposts for some trainees.

I think that the most significant mind game is that the course is expensive. After paying this ridiculously high sum it is human nature is to convince yourself that this must be valuable training. When trainees start suffering from mental exhaustion, the non-refundable tuition fee keeps them from withdrawing. The cost is generally over £1600 (around $2000 USD). The cost of the course verses the low salary that an EFL teacher will make is incredibly disproportionate.

The class is designed using experiential learning. I experienced this as a guess your way through the course. If they eliminated the experiential learning component I think that the class would take about fifty hours to complete, instead of the one hundred twenty hours that are currently required. This time commitment does not include out of class assignments which can easily be extraordinarily time consuming. I felt that they did not enhance my practical teaching skills. To define time consuming, I had no social life and  no time for church. This would have been tolerable, if I had felt any of this improved my teaching skills, it did not.

There are other certifications that are less expensive and provide new English teachers with some basic skills. In most parts of the world these certifications are sufficient. When it is at all possible, I suggest taking one of those EFL courses combined with live teaching experiences. It is easy to volunteer to teach refugees or begin by teaching private classes. 

I think the biggest downfall of the CELTA is that the massive time commitment only includes six hours of practice teaching, and half of that is wasted in guessing the formulaic teaching method. The guessing is done through trial and error . I did not find this a useful way to use such a limited amount of practice  teaching opportunities.