why do anime characters only have flip phones in modern anime
Because Koreans and Japanese prefer physical buttons. (I personally want slider phones to come back)
If you think their flip phones have worse characteristics than modern smartphones you are wrong.
For example take 'Index'
Toma uses a flip phone because that's what he used in the source material.
While satan uses a smartphone because they never specified what she uses and hence could use a up to date model in the anime.
Don't forget about Kuroko's "phone."
>Kamen Rider OOO shilled iPhones and iPads
>also had some good moments with footage of the villains being put on Youtube and them lamenting how humans have got crafty over the last thousand years or so
flip phones have more comedy potential
also cute girls can attach cute charms to them and stuff
KEIT-AI the animation's MCs use iphone.