That has nothing to do with the taskbar icons which are huge and not appropriate for a working environment.
Adjusting the scaling is global and not taskbar specific.
It may look "nice" to some casual users but for those working with dozens of programs simultaneously, the Windows 11 taskbar restriction to a single row and these huge icons at 100% are a pain.
To reduce the icon size and get two rows you can use third party software like ExplorerPatcher.
I hope Microsoft will find a way to pay respect to their long standing users in working environments and not just create an OS interface for casual use.