That use-case doesn't need the double-spend protection, so it doesn't need blockchains.
I'm seeing lots of "web3" use-cases proposed that are just plain old public key cryptography, but people think that reusing wallet's private key somehow makes it new and magical.
How else would you create a decentralized, distributed, immutable ledger of likes (or other events) in a trustless, permissionless, uncensorable, fault-tolerant, and consistent way?
Exactly like cryptocurrency, but without the planet-incinerating part that selects the longest chain. If you treat "like" as idempotent, then you don't need double-spend protection, so you don't need to select the longest chain.
In trendy terms, like IPFS where you pin your own signed like messages.
Note that identity verification, forgery prevention, and distribution of messages are done using "web2" technologies, even in blockchain systems. The hard part in blockchains is literally only the double-spend protection, so if your problem is not about spending money, they do nothing.
So if a blockchain was leveraging a proof of stake [1] along with zero-knowledge rollups [2] for scalability/ compute you would have no arguments for it? In that hypothetical example it seems like a much better alternative to IPFS with no moral qualms.
From the environmental perspective PoS blockchains are acceptable (merely very slow and inefficient rather than outright planet-eating). They're still pretty dystopian long term, since they're fundamentally plutocratic and naturally leading to an oligarchy.
Ethereum PoS is perpetually "almost there" like Star Citizen and the Year Of Linux Desktop. I don't think anything they say matters until they actually shut down the PoW system (which I don't think they can).
Either way you will still have to pay gas fees to the staking overlords for the permission to do anything on the blockchain they control. I'd rather have a federated/self-hosted system, and drive it down to as close to free-of-charge as possible by improving its efficiency.
Do you have any specific questions or concerns about how they are going to shut down Ethereum's PoW system?
I've been following development very closely, and to me, the process is pretty straightforward. They've already run the process several times successfully with production data in shared development environments.
And what good is the ledger if the vast majority of users interacting with it do so through very centralized, very old fashioned platforms controlled by a single entity?
I'm seeing lots of "web3" use-cases proposed that are just plain old public key cryptography, but people think that reusing wallet's private key somehow makes it new and magical.