Yes, it would be easier to notice the chests if they looked like chests. BUT the thing with chests is that you can't open them if there's a block placed over them, which is bad if you're being tricky and hide them. The chests they use now, you can loot even if there's a block on top. They should just stick with the ones they have now, you'll get used to it. And if not - the maps have been played so many times that you know where to find the chests.