I keep everything in the cloud as well. Documents are either in GDrive / Dropbox and photos are in iCloud. For sensitive documents I created an encrypted disk image that I store in Dropbox and mount when I need access to it, which is pretty infrequent. I periodically backup content to a NAS and I backup the NAS to B2.
I use Insync since this seems to be one of the few softwares that works on both Windows as well as a Linux box. But it has crazy privacy concerns. I have been able to view documents uploaded on someone else's account on my Insync app! I have no idea how many folks have seen my documents/data.
Take a look at Cryptomator. If offers transparent encryption across windows, Linux and MacOS. Desktop clients are free, iOS/android costs a one time fee.
