Isn’t the internet already a pretty decentralized computing system? (Not a rhetorical question, I’m interested in your opinion.) AWS is cheap and effective; or you can buy your own hardware and run your own computing resources.
I don’t think there is a single reasonable use case for Ethereum. Decentralized smart contracts on a blockchain? Maybe someday, but you certainly don’t need yet another native cryptotoken to fuel it.
Ethereum in my opinion is a smash-‘n-grab-the-money job that turned into a full-fledged, grade A scam.