Input: User identity, money.
Output: Digital services, site subscriptions, digital assets, in-game items, NFT's representing real world assets held by trusted companies (wine, event tickets, tokenized securities).
None of this requires oracles and exists today.
Your mistake is thinking that just because the base layer is decentralised that we're somehow not allowed to connect to companies we choose to trust, just like we all already do.
Then it becomes interesting because there's a programmable market for these assets/services that didn't previously exist because the underlying value was not represented in an exchangable form. The outputs are also inputs.
Ethereum is the trustless, standardised substrate on which trusting parties can interact.
HackerNews will continue to fail to see the utility of this system for years to come until it's mature and undeniable. It will be an interesting case study into how experts missed the potential of emergent technology in the same way we look back on yesterday's commentators not realising the disruption of Amazon or the internet.
As to your second point, it's unlikely the end user will ever want to transact on layer 1. Layer 2 technology is making steady progress. See l2beat.com for examples.