The little one sees of the roof trusses looks like truss roof trusses, which are self-supporting if they are properly dimensioned. But in addition to load-bearing walls, there are stabilizing walls, which, for example, limit how much the house moves when it's windy. There are already very few walls in that building structure, so if you remove even more, you might get a house that creaks a lot when it's windy.
Even without load-bearing interior walls, it's normal for the ceiling to sag a few centimeters when a wall is removed.
It is already an open floor plan, and it might be nice for your guests not to constantly see the mess in the kitchen.