I see several youtubers that like to land their mobs on a full block or a slab or something above a hopper. Is there any benefit to this, over just putting them on the hopper directly?

I’m specifically doing a piglin trader at the moment, my piglin is just standing on the hopper, but I haven’t finished the automation yet.

I also have my spider spawner trident killer right on the hoppers, and my mob drop farm lands on hoppers. I seem to get the loot and xp just the same as landing on a block.