There is a reason for them to not report on it. They were still working on the game (and they still are even). They don't know how the performance will end up at release until it's there. Reporting on it too early just misinforms people.
Well, surely if they're playing it 2 weeks before it's due to launch and it runs like garbage, they'd think "hmm, maybe this won't be ready in time. I should probably tell people about it" rather than just being greedy and sweeping it under the rug. Also, you can be honest about issues you experience with the people watching your content. If it gets better before it's released, you just make an update video stating you've seen an improvement over time. No need to hide it
I've watched a good bit of the game so far. I don't think anyone hasn't discussed performance. It's not something being hidden, it just isn't where it should be or where they want it to be, and they've been clear they're going to continue working on it to get it where it should be. They just can't hit that target for launch. Delaying it wouldn't be great either because plenty of people will be able to run it, just not as well as it could be. That's OK in my opinion.
They do. Look at city planer plays video. According to this, I can hope to get a bit more then 30fps at 1080p with medium details with my 4070 ti and 7600x. Beyond that, I‘ll get a slideshow. For most PC owners out there, the game will be unplayable in it‘s current state.
Most YouTubers have beefy rigs. Also, the preview build could have some kind of limitation which was never intended for the final release but which improves performance