1, which is difficult to achieve: the single training cost of Vipassana is not high, and the hierarchical system stipulated by the system is quite "strict". How much training do you have to take to reach any level before you can start any course?
2, high reproducibility: the sequence of Vipassana can be bought online, and the teacher will know it after reading it several times. Some people make up their own sequences with music, which is not authentic enough.