The problem happens afterwards. Most startups, once they find their niche and start selling, they stop innovating.
You have to keep innovating to be relevant.
You have to innovate on optimizing your product.
You have to innovate on use cases.
You have to innovate on new features.
Invest in an R&D department in your startup. It will pay for itself very soon.
We built our own telephony hardware. We then built a telephony platform. Next we moved up the stack and built a cloud contact center. We are still innovating. We have now ventured into speech. Cos' we know, the moment we stop innovating, we stop becoming relevant.