Although Windows 11 shows icons in an Overflow menu on the Taskbar, it is possible to stack or unstack icons on the Taskbar using this tutorial. You can do that with the help of the Registry Editor.

Add the TaskbarSi value to the Windows Registry. Change value data to 0 for a small taskbar or 2 for bigger icons. Restart or log out for it to take effect. The easiest way to change the Windows 11 ...

The Windows 11 taskbar may look modern, but it's surprisingly rigid. Beyond a few basic tweaks, Microsoft gives you very little room to personalize, even less than in previous versions of Windows.