Would really love to see a web api standard for on device llms. This could get us closer. Some in-browser language model usage could be very powerful. In the interim maybe a little protocol spec + a discovery protocol used with browser plugins, web apps could detect and interface with on-device llms making it universally available.
https://webmachinelearning.github.io/prompt-api/
Already in Chrome as an origin trial: https://developer.chrome.com/docs/ai/prompt-api