It would be cool if you could Mesh multiple HA servers together.
Example:
You have your main Homeassistant running on a central server on your network. There also is a second server only meant for a specific task like handling AI in local Assist. Another feature request meant that there should be a Mixtral chatbot integration that runs locally. You could make a seperate server just for running the chatbot.
Or if you have a homeassistant in a big building you could have a seperate server for each parts of a building all connected to each other.
Mesh means that all servers would be able to handle requests, which is not really what you describe.
Your description is to offload some work, which can be done with add-ons already or with services that have a well-known interface, like database servers or MQTT brokers.
You also suggest workload balancing, but that requires a setup with hardware that can be shared or coexist, which is often not the case with many of the technologies used in IoT today.
You also mention a big building with many servers, which would still require a main server, but this setup can already be made with the Remote HA integration.
True and only way to use multiple HA iinstallations with these technologies is to split it out to its own unit, like with a MQTT gateway.
This will not remove the single point of failure, but it will make it possible to connect multiple HA installations simultaneously.
- Feature Requests - Home Assistant Community