And that's also exactly the problem I have with Ethereum, so I don't understand why you on the other hand don't insist on a "killer app".
Bitcoin, as a value transfer tool, has characteristics no other medium of exchange can provide, like its strong censorship resistance. While other altcoins provide that too, none is as secure as BTC.
Ethereum positions itself as an application platform. That's completely okay. The problem is with the applications themselves. They should solve a real world problem. And that's where I think most Ethereum projects are failing. They are creating solutions in the virtual space which are not related to a problem in the real world. Not even in a "virtual world" outside of the crypto space.
There are very few exceptions, I think for example that Dai is really an interesting project, even if I wished it would be even more decentralized. But most other projects are basically marketplaces either of cryptocurrencies or tokens (which is why I wrote about the "circlejerk" problem) of "some virtual data entity", like AI agents. These marketplaces normally don't really need a blockchain to function.