For the tinkerers out there: Windows 11 actually supports a fourth size option not visible in the menu: "Extra Large." This is hidden in the Registry Editor.
Sometimes the scroll trick feels too loose, and the presets aren't precise enough. If you want to change the scale of everything (not just icons, but text and taskbar too), you need Display Settings: windows 11 desktop icon size
The fastest way to resize icons is through the desktop's built-in context menu or a simple mouse shortcut. For the tinkerers out there: Windows 11 actually
Before you dive into menus, know this: Windows 11 has a secret weapon that works instantly. but text and taskbar too)
You will see the icons resize live in about 2 seconds. This is the fastest way to get exactly the size you want.