This has pretty much always been the case. You've never been able to build production-level software in 2 days (not even in the age of AI, no), so it's always been about having a UI with mocked data.
I did a lot of hackathons when I was in school more than 10 years ago and that's how they all were and what every team did.
You'd be surprised about how much production level software was built in two days — the fact that organizations are usually unable to do that is what gave rise to the agile movement, though it falls apart as soon as management asks for agile coaches and for agile teams to document their processes for others to use.
Had a "project" course in university for CS. Implemented a working SaaS app for hosting ML models (before AI).
Winner in our category had a powerpoint and a poster, no one even looked at the implementation. I learned something that day.