You're right that LLM context is the limiting factor here, and we generally don't expect machines to be used across different LLM contexts (though there is nothing stopping you).

The utility here is mostly that you're not paying for compute/memory when you're not actively running a command. The "forever" aspect is a side effect of that architecture, but it also means you can freeze/resume a session later in time just as you can freeze/resume the LLM session that "owns" it.