Full-size and compact SUVs differ most usefully in how much vehicle you must manage to carry the people and equipment you need. A full-size model generally offers a larger body and more room for substantial passenger and cargo tasks. A compact model generally asks less of a parking space and can be easier to accommodate in a crowded daily routine.
Those broad differences do not settle the purchase. Seating layouts, usable luggage space, payload, towing equipment, efficiency, and ride behavior vary by model. Compare specific vehicles with the same household load, then decide whether the larger footprint earns its place in ordinary life.