I am building a movable narrow island / kitchen prep table out of plywood and would like to know what would be the strongest joint for it. It will be mostly supported by the cabinet box sides which are 48" long and 32" tall. The cabinet will be 16.5" wide. I think a 90 degree butt joint on the bottom will be stronger since the weight of the sides will be directly on the bottom board rather than transferring the side load through the pocket screws. The top will have a granite slab so there will be a lot of weight on the cabinet box. Ignoring any finishing or what looks better, what is going to be the strongest method between a 90 degree overlapping butt joint versus a pocket screw. I was also thinking of doing a rabbet joint on the bottom but then I would have to adjust the pocket screw a bit and do the rabbet which takes more time. Drawing not to scale, it will be much taller.
Additional info: I am filling the cabinet with drawers on each end. There will be a center vertical board in the middle to help stabilize and split the cabinet box.
Updated: Here is the solution I chose