Years ago in my bachelor days,I went through a Cajun phase where I regularly visited friends in New Orleans to party. I picked up a taste for zydeco. Of course, the accordion is integral in zydeco music and the best practitioners use the instrument to motivate people on the dance floor as well as make them cry during ballads. My favorites are Clifton Chenier, his son C.J. Chenier, and Buckwheat Zydeco. Cedric Watson is terrific as well. Great fun and musicianship from an instrument too often associated with Weird Al type clowns.
Why not accordion ?
To my point of view it's one of the most universal solo instruments, but not widely accepted in any classical or jazz orchestras or bands. It's also sophisticated. I'd say extremely sophisticated. In order to deliver smooth and artistic sound it may require long and extensive practice to handle bellows and position your hands properly. In addition there are two button boards that can deliver sophisticated polyphonic parts that can create an impression of small band inside one instrument. You can also count on fingers great accordionists while you can have an endless list of great guitarists or saxophonists.