That isn't a use case for *Bitcoin* in that it's something Bitcoin doesn't actually accommodate on a fundamental basis: Bitcoin nodes don't need to store or provide access to historical blocks to operate.
Then just use something that stores the data in utxo set such as Bitcoin Stamps:
https://finance.yahoo.com/news/bitcoin-stamps-nfts-gaining-ordinals-225153058.html As an aside the data you're talking about doesn't make a lot of sense to store this way: E.g. "seed phrases" -- because the stored data is public the *only* security for it comes from the private key used to encrypt it. You could instead skip the stored data and derive all the bitcoin keys and website passwords from the same key with no storage. Presumably if your key is secure then you have to store it too-- most mediums that can store 256 bits can also store 2kb. I'll guess your key is really a passphrase which means that the thing the attacker has to attack is just that and not aes-256. A human memorized passphrase usually has less than 70 bits of security, so even worse to make the data public in that case.
it could be literally anything. say i came up with this fantastic recipe for spaghetti and meatballs.
[As a bonus: surprise the same person financing that copyright litigation against me is financing several of the high profiles ordinals companies. Though I think the pretty clear fact that ordinals are being used as an attack on Bitcoin to destroy its decentralization (by driving up resource costs, by increasing the legal risk in running a node, by being used to justify vexatious litigation against tech people) doesn't mean all its users or the people who originally created it intended it as an attack. But it's the effect that counts.]
sorry you're being sued that's really surprising but what would even be MORE suprising is if the plaintiff won.
now you presented a bunch of use cases for bitcoin and they are all fine to some degree or another but i think my proposed use case isn't like the bottom of the list.
Each of these cases Bitcoin can help with because it removes trusted third parties from the process of either transacting or storing your wealth, trusted third parties which fail to deliver a stable system, can capriciously interfere with your right to associate with others, or otherwise act against your best interest. These are examples of the use cases Bitcoin set out to solve, which its fundamental properties are designed to satisfy and are mostly difficult to impossible for other systems to solve (except to the extent that they imitate Bitcoin's design).
that's all a nice theory and we like to think that's how it works in practice but the way it usually works goes something like this: i have some cash in my bank account. I transfer some of it to coinbase. The bank allows that transaction to go through. Then I have to start trusting coinbase to let me buy bitcoin. Once I buy it on their platform and pay them any fees which I don't like paying fees but that's non-negotiable, I have to trust them to let me send that bitcoin to my external wallet. If i ever sell some of my bitcoin or pay for something with it, I need to tell the IRS about it. Is the IRS my partner or they a "trusted third party"? I'd rather them not be in my business but I don't see how that can not happen if I'm involved in bitcoin...