I understand etymology has to use history to present a case, but I don’t know a single BrE speaking person that’d write a current text with -ize endings. The OED aren’t prescribing current usage with their stance.
As a BrE speaker, I do use "ise", but "ize" is not unknown, especially in science (I believe that the British published journal Nature has it as their house style). Recently I think it has been declining as it has been identified as "the american version".