What's most relevant is that the fact that these chains ever let data expire is simply an artefact of their design: they could be changed to never let anything be deleted ever, and still pay people for storing it via mining and fees.
Distributed encrypted overlay storage networks for both reliable and lossy storage, or both in one, will see a lot of ongoing development. Though it won't be as efficient, expect to also see people renting out precomputed space to miners mountpoints at various oversubscription ratios, over various chosen input ranges beyond just random.
https://file.app/ $0.0292 / TB-Month
https://siastats.info/storage_pricing $4.29 / TB-Month
https://aws.amazon.com/glacier/pricing/ $4.00 / TB-Month
Consider if those are prices for worthless lossy storage. Chia depends on the miner being able to find precomputed answers on storage, if that storage is constantly evaporating the miners data out from under them, the miner has no answers, and has to waste even more time-energy-money backfilling those holes in their rainbow tables again. Then also consider if those prices meet the hard economic reality of actual long term raw storage pricing, versus being subsidized by foolish investor rounds, loss leader sales promotions, etc. Today, $685 / 18 TiB / 12 mo / 5 yr = $0.6343 per TiB-month-lifetime. Just for the raw disk, before paying for everything else needed to export it to the world over whatever network. At $0.03 per T-m[-l?], FileCoin is clearly a counterparty bankruptcy risk to your data. Even if people are yield farming their otherwise unused disk extents off their home and business hardware into FileCoin for fun, those users are pricing their slack space way too low to ever buy even a pizza with their earnings. SiaCoin and Amazon are pricing closer to reality after export costs and profit. The sweet spot between price, capacity, watts, chassis volume, speed, etc is always moving. https://www.zdnet.com/article/worlds-largest-ssd-hits-100tb/ Apricorn ADT-3PL256F-18TB 18tb Aegis Padlock Dt Ext Secure Usb 3.0 256-bit Aes Secure, lol.