It would be helpful to be able to run the add-ons in different instances (on different hardware) to increase the total available power of the system.Especially with local AI which is quite demanding.
One instalation could act as the main and other, lightweight, could only run one or more addons as services.
Even more could have high availability functionality with multiple fall backs or running in parallel
Check out my feature request for the same idea: Manage Docker on Another Host
High availability is unlikely to ever become a feature. It is very niche.
However, sustainability and allowing users to expand their system without discarding their weaker hardware is a more realistic goal.
EDIT: My point with sustainability is that we can rightfully encourage any user to start with a Home Assistant Green knowing that they can always add additional hardware and their Green will not suddenly become a useless paperweight. Essentially, when you outgrow the Green, move your addons to another system and keep Home Assistant Core on the Green.