the fee pays into an endowment. the endowment is only paid out to miners if the block reward in USD terms is too low to justify storing the full weave.
the size of the fee is a function of 1) the amount of data you wish to store and 2) the estimated cost of storing the weave between the current time and the end of the storage period ("forever" is actually assumed to be about 200 years for these purposes).
If you were to store 100 TB on the weave tomorrow (the weave is currently 10TB), the block reward would remain the same, but the endowment payout would trigger much sooner.
The endowment fees are sized with the assumption that the endowment will have to pay out immediately and until the end of the 200 year period.
Ah, that makes sense. I think their 'sales pitch' would be more compelling to more technical users (which I assume is the main initial demographic) if the 'forever's had asterisks and the 200+ year assumption was prominently displayed on landing page.
That shifts my expectations from "economically infeasible lie" to "small fee may not be so small, but feasible with proper stewardship and valuable for certain use cases."
In the crypto/DeFi space, superlative marketing copy is more likely to be interpreted as 'potential scam' than other domains IMO.
Seems like an obfuscation of the economic problem that doesn't solve it.