The only data loss to Google that I was able to find was [0], where a single datacenter was hit by lightning 4 times in short succession, and 0.000001% of disk space in said datacenter was lost. And only because the lost data consisted of recent writes that had yet to be backed up. And only because the lightning affected the AUX power systems in a way that they have since committed to fixing (or perhaps have fixed).
IMO, cloud storage is the most reliable way to store data, and Google the most reliable. I never know if I'm going to drop my laptop and lose all work. Or if the harddrive in my server is going to give up and burst into flames. But the great thing about cloud storage is that it abstracts away hardware components and failures so it's somebody else's problem. And they worry a lot more about data loss than I do. Cloud data storage is designed with the assumption that hardware is faulty. Spread redundant copies of data to geographically isolated datacenters, and you're much safer than some admin of averagejoe.com keeping his data on a single harddrive in his closet.
[0] - https://status.cloud.google.com/incident/compute/15056#57195...