Landing pages and waitlists are becoming too common. It's very common to come across a great product on Product Hunt, only to find that it's just "validation" and doesn't even exist. Waitlists are a signal of vaporware and many just avoid them.
If you're trying to prove a value proposition, I find that a survey works better than a landing page. PowerPoint decks work too. You can do something similar without being deceptive. Or you can just go to a subreddit of your target market and see what's popular or what people are complaining about.