My current approach is to use two external hard drives for local backup, one automatic and one manual, combined with Backblaze B2 for remote backup.
Photos are initially stored locally on an SSD, grouped into one or more folders per day. Post-processing, if necessary, is performed on the files stored there. Files on the SSD are automatically backed up to the first of the external drives using the File History feature built into Windows. (Mac users can use Time Machine to do the same.) The File History layer contains the most up-to-date backups and is rarely behind by more than a few hours (typically, the drive is plugged in and a backup manually initiated shortly after the files are loaded onto the system).
These folders are then regularly copied to the second external hard drive, which is intended to contain a readily-accessible and complete archive of my photos. Older folders of photos are periodically removed from the local SSD to free disk space, but only after they have been backed up to both drives. This step is performed less often and may be a few days to a few weeks out of date (depending on when I get to it), though the data is still on the system SSD and the File History drive.
Later on, the folders on the second external drive are rolled into encrypted archives, each containing one calendar month's worth of photos, and uploaded to Backblaze B2 using a program called Cyberduck. Only whole months of photos are uploaded at a time, so the data there can be a month or more behind the local storage, but any data that is yet to be uploaded would still be redundantly stored locally.
My File History drive may fill up faster than the main archive drive because it covers all my personal data on my system, not just photos, and may store copies of photos that are being worked on or deleted. As such, this does mean that older backups files on this drive may need to be deleted. By the time this happens, though, the data would already be on the second archive drive and on Backblaze B2, and I generally don't care about older intermediate copies stored on the File History drive.
In all cases, at least two copies of all photos are maintained, and many will have three copies.
This backup scheme has proven itself before. I've had the archive drive suffer unrecoverable filesystem corruption at one point due to a botched USB transfer. Downloading the archives only costed a few dollars, and while the B2 archives didn't contain the most recent photos, I was able to retrieve the rest of the images from the File History drive.