I'm starting to think people impressed by LLMs are for the first time in their life not using a hammer on fastening screws and deeply impressed by tools that font fight them every step of the way.
You don't need to prove it, that was never a requirement. You can simply say it. The only complication is that there's a fair number of people who, for some reason, really want to pass LLM output as their own. They are present on HN too. But here's another ancient trick to overcome that: reputation. Either the reputation you already have, or reputation you build over time. If you have a reputation as an honest person with genuine interest in software, you really don't have to worry, and you will have audience for your work.
What was the point before? To have fun, build a community, and to get attention of hiring managers. The first two reasons are still there. The third is more questionable, but there's still plenty of companies that hire based on what you know, not how well you prompt.
The credit for the Doordash meal should be given to the person placing the order. If it weren't for their amazing prompting^Wclicking skills, which make food materialize out of thin air, we would not be eating today.
Of course there is -- ask you about it.
The coolest interview process i ever participated in (at MIT Lincoln Lab) was structured this way, and seems 100% LLM-proof. The interview was: give a talk about a cool/impressive technical thing you did for an hour and then answer questions from the interviewers about it for an hour. No way to succeed there without actually understanding.