My DS is 14 and he has a phone. He mainly uses it to WhatsApp and call us - he used to find it convenient to be able to message us about plans/changes during his break times and after school. He doesn't use it that often; but then we have a lawn mower that we don't use over 99% of the time, but we still need it.
He now cannot do this and he has to go to the school reception to ask them to phone us - like a nursery child asking a grown-up to speak to mummy or daddy for them.
I judge parents (and schools) who assume that, because they obviously don't have a teenager who can be/has been properly brought up/disciplined to use a phone responsibly and sensibly, all teenagers shouldn't have a phone.
Phones are here to stay and it's ridiculous trying to be like King Canute and denying they exist, or at least keeping young people from learning about them until they are 18. Do we do this for other life skills? People who didn't understand the internet in general used to scoff about what a pointless fad it was, and that we have books, so nobody actually has a need for it.
Do we ban PSHE lessons at school about money management, budgeting, loans, interest etc. and assume that they will be able to instantly learn once they're an adult and old enough to need that knowledge?
Saying "They can have a brick phone" is like the people who parrot "Bring back national service!" without really having any idea of how it would work in practice, but they just think it makes them sound clever and original. Modern life is designed around having your whole life on a smartphone - I'm amazed at any parents who would genuinely want to hold their children and teenagers back from learning about and becoming familiar with this essential part of life and hinder them in this way.
The main demographic of people who have brick phones - many elderly people - are also 'coincidentally' the same demographic that ends up digitally excluded, struggling to stay integrated and isolated from society in many ways. Is that really what you want for your children, who will eventually simply not have the 'luxury' that current old folk have of just about being able to manage without one.