Say you have a clothing store listing page and you filter for only "Shirts". Well, the filter that has "Material" might remove (or disable) the option for "Denim" because that is only for "Pants". So that state needs to be computed some where. My thought was, "Ok, refetch the whole thing with the updated options within the form (disable options that can’t be combined together) + the product results for those filters". But that was just a lot of HTML to ask for after each change.
So decoupling it so that the form never refetched, just the results, made it a lot snappier. But you still have the form state issue where you want to update the options based on selections. So the form became a little Alpine data component and the results stayed as an HTML partial.