8TB HDDs can be had for around $100 each. Four of these in RAID5 gives you 24TB. That's enough to backup 5000 DVDs (single layer) or 2800 dual layer DVDs.
If you're protecting your data from minor damage and decay of the DVD that stores it, having an ECC file stored elsewhere (a newer DVD, or HDD, or cloud) is the lowest effort and cost option but still a big step forward in resilience. It doesn't matter how long each medium lasts, all that matters is that they don't fail at the same time. Pick your HDDs from different manufacturers, models, or batches and the chance that all fail within the same short time period without external influence are exceptionally low. And when one does fail you replace it. You'll never get a one time perfect solution, you're just buying time to rebuild your resilience when you take a hit.
If you're protecting against the complete destruction of the disk then an ECC file won't do, you'll need a full copy. Or multiple copies, and in multiple locations. Or on different mediums with very different reliability curves. You might want to protect against internal or external malicious actions, technical obsolescence of the medium or data format, vendor lock-in, or political instability. No one size fits all solution, certainly not a cost conscious one.
For my dad, and anyone just tech-savvy enough to select a bunch of files, put a disk in the drive and click "burn", the choices are either DVD (which deteriorates) or a cloud solution. Anything else is too much, including "here's a NAS, it'll last you forever as long as you keep it plugged in".
Then you moved to the (unsupported) argument that consumers don't have reliable options. Then to the (unsupported) argument that hard drives fail after 5 years. Then to the argument that some users are not tech savvy enough to use anything more complex than a CD.
The last one is the only realistic yet still relatively weak complaint. It doesn't invalidate in any way the option proposed in the article. Looking at dvdisaster creating an ECC file is at most just as complicated as generating the data you're looking to protect. Using a commercial cloud storage solution is equally straight forward. A consumer friendly NAS is very easy to use while not so obvious how to fix in case of failure but that's why you're there to set it up and set a sync to the cloud(s).
I hope you taught your father how to select appropriate quality media blanks, what are the optimum storage conditions, how often to check that the data is still readable, what to do when a disc becomes unreadable or very hard to read, how to replace the optical drive when it fails or there's dirt on the lens, and so on.