Battery, space, and startup time limitations probably. As it is mirrorless cameras can only get like 350 frames per charge, so adding more power hungry features

Battery, space, and startup time limitations probably. As it is mirrorless cameras can only get like 350 frames per charge, so adding more power hungry features like GPS or LTE would only make thay worse. Camera bodies are packed as is, so having a limited amount of fixed storage (when there is perfectly good removable options) take up valuable space is not an especially appealing trade off. And lastly / most importantly, I need a camera to be ready to go as soon as I turn it on, I don't have time to wait for a full OS to boot up. Standby mode could mitigate that but see previous concerns about battery life.