To export your Google Maps starred locations:
Go to Google Bookmarks: https://www.google.com/bookmarks/
On the bottom left, click "Export bookmarks": https://www.google.com/bookmarks/bookmarks.html?hl=en
After downloading the html file, run this script on it to generate a KML.
It's hacky and doesn't work on all of them, but it kinda works.
I updated the regex for lat, lng based on the most recent google response, here's the gist: https://gist.github.com/ngzhian/73c51bcb44c8bfd8dc02d4aa538fb83f