IELTS exam assess the proficiency of a student in English language on the basis of four modules. These modules do not come with a fixed syllabus, thus getting hold of the authentic material to prepare for the exam can be a bit difficult. Apart from the Cambridge books and Cambridge certified material, various blogs also provide study material to the students. However, not all of that can be trusted.
The blogs might provide material which is either too simple or too complex as compared to the material used by Cambridge University. The IELTS exam questions are actually set by this university only. It is fine if the material from the blogs is being used for the sake of practicing the questions, but students should not set a bar based on those.
Besides, there are modules like writing and speaking which cannot be properly practiced without getting a feedback. The writing assignments need to be thoroughly checked and speaking practice cannot be done simply by sitting in front of the computer screen. Both these modules require human touch.
The blogs might not be able to convey the short-cuts and time saving techniques to the students aspiring to appear for the IELTS exam. This exam being a time bound assessment requires effective time management. Virtual teaching might fail to serve this purpose.