So, in light of Google deciding to prune inactive accounts, I am paranoid. So I decided to look up Every Google Drive File I Own Or Was Shared With Me, decide if I care if it's lost, and then downloaded my own copy if "yes, I do care".
The ONLY way I got Drive to show me Absolutely Everything was to:
- Go to https://drive.google.com/drive/search, which you can do either by clicking that link or going to Home, scrolling down, and then click "Show More Files"
- List the files in reverse-Last Modified order.
This procedure allowed me to view files that had been shared with me since 2010, which I knew existed but couldn't get any other view to show me.
I would suggest backing up things that seem important to you now. We are technically past the deadline that Google set on December 1st. Thankfully, nothing I wanted to download seems affected yet.