Windows 11 failing at designing consistent rounded corners

I don't know why a trillion dollar company can't get UI right 

The only consistent thing about Windows is inconsistency.

Native Windows 11 applications often follow the design language closely, demonstrating consistent rounded corners. However, third-party applications may inherit their own styling, leading to a less cohesive look.

This will be true till the end of times.

From my own experience, it's also common to see inconsistencies between system apps and third-party apps; Microsoft’s own tools usually have that uniform look, while others might not follow the rounded theme as closely. If it bugs you, you can play around with graphics settings or check for updates, as Microsoft tends to roll out patches to refine these design quirks. But let’s hope they smooth it all out soon, because who doesn’t love a polished look?