The question is whether it works well in real use, and no landing page can show that. I can likewise put up an email subscription page for a $20k flying car.
Making this product work 50% of the time takes some serious work, but making it work the 99.5% of the time which would make it qualify as a keyboard replacement is something else entirely.
I wouldn't waste potential customers time with a landing page like that, and their video is downright insulting. Spend your time and resources making something that works instead.
Anyway, with all the buzz around hardware startups, I would expect more landing pages like this to crop up. People simply don't realize how difficult making good tangibles is, but they will find out soon enough.