As of 2017, SketchUp changed to using an embedded Chromium web library instead of relying on the OS’s libraries. This was done to improve consistency in the face of a great many issues from different OS versions of the web libraries. Most web-related items in SketchUp already use Chromium, and the rest will be migrated at some point.
I believe that folder is where the embedded Chromium web library now keeps its cache (the equivalent to the folder where any other browser keeps a cache). If you prevent SketchUp from writing there, it is likely that many items that use the embedded Chromium will cease to work correctly.