If you want a radically different dock that shows just the apps that are currently running on your Mac, a simple Terminal command will get it done—but proceed with caution, because a bug sometimes prevents you from later restoring the dock to its original state, forcing you to reset the dock to its default settings.
If you’re ready to take the plunge, open Terminal and paste in this command: defaults write com.apple.dock static-only -bool true; killall Dock. This will remove all pinned apps from the Mac’s dock and switch to a display of running apps only. To restore the dock to its previous state, this command in Terminal should work: defaults write com.apple.dock static-only -bool false; killall Dock.
If the restore command doesn’t work, reset the dock to factory settings with the following command: defaults delete com.apple.dock; killall Dock. This will change the dock to how would look after a clean install of macOS.