Marie Kondo is different from other organizers because she has a fresh, new approach. Her techniques are from China where they all must organize their belongings due to having little space. She also has a different personalitu and air about her that many find refreshing. Some just like to watch her to poke fun at her, sadly.
There are many viewers who have found great help with her organizational skills due to the fact that she is different. She has unusual ways she goes about doing things and also has interesting and unique ways she teaches those things. Whatever it is, it all seems to be working for her and for the show.
We don't know the quality of other organizers who have not reached the public eye. We do know that Marie Kondo has demonstrated her effective tidying techniques on video, and written about them in a book that has sold millions and apparently impressed all those readers.
Marie Kondo has shown the ability to talk to 'everyone' rather than just groups within her industry. she has shown the gift of making her ideas accessible and relevant to all who own clothes, papers, a room, a house and more.