Some LLMs can be downloaded and used by those who are interested. But to run this LLM and AI model requires programming expertise that is beyond the reach of the general public. This is the reason why ChatGPT, Bard and Copilot are popular because they can be used directly without the headache.
Most recently, Mozilla has introduced Llamafile that can be run directly on computers that use the operating system. Windows, macOS, Linux, OpenBSD, FreeBSD, and NetBSD. LLamafile is launched directly like a normal software and runs directly on the user's PC without requiring an internet connection to function.
Mozilla also stated that with Llamafile, users will have personal artificial intelligence. Each prom entered will not be monitored by anyone and it can be accessed at any time according to the user's wishes. Mozilla calls this concept local AI.
This is the same as Google gave the Gemini Nano on the Pixel 8 Pro. Users of these devices can use the AI features offered and all processing takes place from within the device and not on Google's servers.