The only use for a dumbphone in my opinion is for the ruggedness and convenience/size factor. Even though there are smaller "smartphones" these days it may be more convenient to use a durable regular phone. When I used to work with telephones there was still a very large amount of these types of phones being sold. They may be limited but if you aren't looking to use any applications and just need a basic feature set these phones will work marvelously. Some users don't want to deal with an "advanced" operating system even though they are made to be one-click these days.