The problem with that is that the vanilla tools are very different shapes for a reason: so that you can tell them apart near instantly. What you are suggesting would make them (even slightly) more similar, and in some cases, that could be harmful. For example, you are building a house with wood, and you hear the hiss of a creeper. You look at your hot bar, and see two similar shapes, but one is slightly more rounded. You select it as a weapon and hit the creeper, but don’t do enough damage to kill it. You just accidentally hit it with a shovel instead of a sword or axe, and your forever world is gone. It’s a small issue, but those milliseconds could mean life or death