Free space in Finder symbol bar is very large in Big Sur

For the most part, may be an idea to simply report this to Apple Feedback; then someone else

could look into the matter (while we'd never know what comes from that) & hope for the best!

Tell Apple if you like, they do read commentary.. Note the Unsolicited Idea Submission Policy

https://www.apple.com/legal/policies/ideas.html {..They won't credit you with 'your new idea'

maybe something you've just conjured ~ that they've been developing for a decade; and so on.!}

• Feedback - Apple

https://www.apple.com/feedback/

Cite example(s) of different areas; each area allows one to provide comment & explain issues, etc.

Hardware Products, iOS and iPadOS Apps, macOS Apps, iCloud, Entertainment and News, Wallet,

Pay (apple pay), Education (apple school manager)

• Feedback - MacBook Pro - Apple

https://www.apple.com/feedback/macbookpro.html

• Feedback - iPhone - Apple

https://www.apple.com/feedback/iphone.html

Software, hardware, etc product feedback can be submitted; just don't expect personal replies!

[Please read Apple’s Unsolicited Idea Submission Policy before you send us your feedback.]

While not addressing your original topic, this indirectly suggests

to look into more than one; and consider those less evident, too.

Good luck & happy trails!🌻🐝

Depending on settings, 'Finder toolbar' and 'Finder sidebar' views can be arranged.

Not sure which instruction or support articles may have guided your effort so far.

• What's in the menu bar on Mac? - Apple Support

https://support.apple.com/guihttps://support.apple.com/guide/mac-help/toc

• Use Control Center on Mac - Apple Support

https://support.apple.com/guide/mac-help/control-center-mchl50f94f8f/11.0/mac/11.0

• Customize the Finder toolbars on Mac - Apple Support

https://support.apple.com/guide/mac-help/customize-the-finder-toolbars-on-mac-mchlp3011/11.0/mac/11.0

There are several ways to customize the Finder toolbar and Finder sidebar.

• Change Dock & Menu Bar preferences on Mac - Apple Support

https://support.apple.com/guide/mac-help/change-dock-menu-bar-preferences-mchlp1119/11.0/mac/11.0

..Also see User Guide TOC overview ~ with access to adjust various details..

• macOS User Guide - Table of Contents - Apple Support

https://support.apple.com/guide/mac-help/toc

• Get to know the Mac desktop - Apple Support

https://support.apple.com/guide/mac-help/desktop-mh40612/11.0/mac/11.0

• 25 Best macOS Big Sur Tips and Tricks | iphonehacks

https://www.iphonehacks.com/2020/11/best-macos-big-sur-tips-tricks.html

Not sure if SIRI could be convinced to aid with user-interface help matters.

Take care & good luck!⛵️🌞🎣🌤