RTOS, Linux, and Android solve different problems, so there is no universal winner for a feature phone. An RTOS starts with deterministic behavior and a configurable small footprint, but the product team must assemble the UI, networking, application, and update layers it needs. Linux provides a richer process and application environment, with the cost and integration work of a larger system. Android supplies the broadest app model, but current Android Go requirements begin far above the 64MB tot...