In Catalina and earlier, the path for Finder folder icons (e.g. Applications, Desktop, Downloads, Developer…) was:
/System/Library/CoreServices/CoreTypes.bundle/Contents/Resources
But as of Big Sur and later, the current icons aren’t stored there anymore. Not even in the assets.car catalog — it contains some of the icons used by Finder, but not the folder ones.
What is the current path?
Edit: To be clear, the folder still contains folder icons, but these are LEGACY ICONS from Catalina and earlier, not the new ones being currently in use.