They do. It's called a PWA. Service workers cache the assets. https://developer.mozilla.org/en-US/docs/Web/API/Service_Worker_API https://developer.mozilla.org

They do. It's called a PWA. Service workers cache the assets. https://developer.mozilla.org/en-US/docs/Web/API/Service_Worker_API https://developer.mozilla.org/en-US/docs/Web/API/Service_Wor...