I store the local drive in a "fireproof" safe (note: fireproof is a bit of a misnomer, since stuff can still burn in a fireproof safe, though it's a better bet than not having one in the case that your home/apartment catches fire).
I also back up to Amazon Glacier as a third offsite backup. One could also use S3 for this, though it might be a bit more expensive than Glacier.
It’s basically the good old 3-2-1 backup rule: Three copies of your data (your production data and two backups) on two different media, with one copy off-site.
For cloud backup of anything i've never trusted Google for shit, even aside from its grotesquely parasitic "privacy" policies (a complete joke of a word for anything to do with that company).
Instead, so far I've tried several and maybe unexpectedly, the most easy to work with and simply functional across multiple machines and several external drives has been SpiderOak. Its desktop interface is shit, but the overall service is easy to use and has never failed me one so far, and it constantly, incrementally conducts deduplicated backups of even minor file/folder changes as long as it's running.
As a second option, Arq has been nice too, though its UI is also rather clumsy.
I've been thinking about getting a NAS, but I feel like I probably need something more than that. It's all pretty new ground to me, though. I think I want to run my own "cloud" from my home that my phone can sync with, helping me organise this stuff and show it to people I want to share it with. But controlled by me and not by Google or some other cloud service.
For online storage I've found cloud S3 storages to be substantially better than customer-faceing services like Google Drive, OneDrive or Dropbox. Amazon S3 may be expensive but you can use Backblaze B2 for $6/TB/month which is as good and as fast. Then use rclone as file browser. You can share single files by generating download link so others can download at 1Gbps no hidden limits.
Is an untested backup really a backup?
What emergency could affect both you and Google, but not lead to the kind of apocalyptic situation where you'd prefer an extra first aid kit, food or ammunition to a hard drive in your go bag? Perhaps if you're on the US West Coast, a huge earthquake is a legitimate worry here.