If you’re on the beta, under Taskbar settings > Taskbar behaviors, you can now select options under Show smaller taskbar ...

Microsoft is testing a new taskbar icon scaling feature that automatically ... The feature is gradually rolling out to Windows Insiders in the Beta (Build 26120.3671) and Dev (Build 26200.5518 ...

The taskbar changes are likely to come to the standard public version of Windows 11 sooner rather than later, since Microsoft is testing them in its Windows Insider Beta channel—that's the second-most ...