There are a couple of makers out there that still offer true archival CD and DVD writable discs. I don't believe they will be around for much longer (1-3 years) on the market. There are alternatives ranging from drives, to cloud and even thumb drives (though I don't trust those just yet).
Here is an old item (2013) but its worth a read... http://adterrasperaspera.com/blog/2006/10/30/how-to-choose-cddvd-archival-media/
The problem with other options is that for archival purposes (say at least a guaranteed 50 years) most other options don't work: obviously the cloud isn't an option (tech companies not only die, but are forgotten in that time frame), and virtually all mechanical/SDD/media storage have some sort magnetic element that isn't reliable over such long stretched.
As the link you gave suggests, a good, archival quality disk is the best option, outside of specialist options not available at retail.