When it comes to design, beauty boils down to two things: fulfilling a function well and bringing joy. In other words, beauty in design is less about aesthetic beauty and more about how well it helps us perform certain tasks.
Simplicity is not the absence of clutter, that's a consequence of simplicity. Simplicity is somehow essentially describing the purpose and place of an object and product. The absence of clutter is just a clutter-free product. That's not simple.