Sometimes Minecraft does not make sense. Let’s get straight to the point.
A stone pick can break stone. An iron pick can break iron ore. A diamond pick can break diamond ore. A netherite pick can break netherite. But a gold pick can’t break gold.
Also, do you know how a arrow usually just bounces off an Enderman? Well, if you put that Enderman in question on a block in the middle of one of those water flat worlds, the arrow eerily hovers above the Enderman. It may not look like it, but the Enderman is teleporting to the same place over and over again.
And lastly, if you look at a spider REALLY closely, like with a spyglass or something, you can see that it is hovering like 3/15ths of a block off the ground.