How do you let users experience your product before building the MVP? i will not promote

After a few failed startup attempts, I realized I'd been doing the easiest part first - building . Everyone says, "Validate before you build," but I'm struggling with what that actually looks like. A landing page and waitlist only tell me if people are curious. They don't tell me whether users actually understand the product or if they'd use it. Figma prototypes help, but designing an entire interactive flow can end up being almost as much work as building the MVP itself. So I'm curious, how do you let potential users actually experience your product before you've built it? Have you used AI tools, no-code platforms, interactive demos, or another approach that worked? I'm looking for real experiences from founders who've done this successfully, not just the usual "build a waitlist" advice.