they still serve a very useful purpose for very many people.
The small size
combined with the screen-protective folding “feature”
is extremely useful to people who need a phone to be no more than a phone
and who frequent any sort of rugged environment.
Ruggedized phones that are not folding are getting to the point where they are pretty good…
but they are still just not good enough at screen-protection for many people who need a rugged phone.
Only phones that are 2G or lower will have supporr dropped, as all the carriers are dropping the frequency for cellular 2G. And just like when the carriers dropped support for analog phone service, all those people had to buy new phones.