I can see this phone being a great fit for certain markets, such as senior citizens who like to talk on the phone, but who get baffled by the complexity of modern smartphones.
I can't see any fit for any person outside of bragging rights. A senior citizen would be better served by a Nokia 3310, which actually has physical buttons.
It's pretty much bragging rights. Or, put another way, it's an aesthetically pleasing signal to those around you that you're part of a movement trying to reduce screen consumption.
The organic foods industry has these sorts of seemingly niche products which are more expensive but become quite trendy because of what they represent for the customer and their peers. Not sure how well it applies here though.
Be careful with this. AT&T shut down its GSM network 3 years ago. The ~only unlocked LTE feature phone I could find a year or two ago for my grandma (who wouldn't be able to learn how to use a smartphone) was an Alcatel Flip 2.