Overall, I think it's a practical idea with a clear audience. If you keep improving the product and make the setup effortless, I can see plenty of founders choosing this over building separate mobile apps from scratch.
Your biggest advantage is simplicity. Many founders don't need a complex native app—they just need a professional mobile presence that works reliably and doesn't require constant maintenance.
If I were considering your product, I'd also want to know how quickly bug fixes and platform updates are released when Apple or Google changes their requirements.