Hicetnunc fees are fixed, and the free market gives an opportunity for other platforms to improve on this if the community desires a marketplace with lower fees (it's much easier to build an alternative to Hicetnunc than an alternative Stripe/Shopify/PayPal). Artists are also given a 10-25% royalty (which they decide) for each resale of a token on the Hicetnunc marketplace. And, of course, since it is all peer-to-peer, you are free to exchange art tokens with no fees at all, save the negligible protocol/transaction fees.
What society definitely can't place value on is a URL to a digital asset that may or may not be there tomorrow, because an uninsured, untrusted value store can't be relied on.
There's nothing saying NFT artifacts have to be digital, though, I'd think. Using them to facilitate trade of physical artifacts would back the trade with (relatively) reliable value stores (physical artifacts) while benefiting from the low transaction fees.
For reference, the last NFT I purchased on Hicetnunc.xyz had a protocol fee of 0.002947 XTZ (around 1¢ USD) and a platform fee of 2.5%, the rest of the sale went directly to the artist's wallet.
To your second point; this remains to be seen—society can place value on many different abstract concepts, "ink on paper" may not be the only valuable vehicle for art and culture.