Yep, and that's because they solve a really really challenging problem you can almost never solve yourself, whether it's payment processing or search.
Creating a simple barebones back-end may be tedious (though I'll argue it's trivial), but it will never be an unsolvable problem for many. Maybe for pet projects, but never for any critical production applications.
It is true that companies can often build their own backends but it is often extremely time consuming and expensive. It takes time to develop these systems and build them to scale and often they run into a problem where early assumptions change while the underlying system is hesitant to.
One of the core value props of a platform like ours is the speed at which you can iterate and develop something while also being given the tools to pivot when you need to. We are focused on building features that allow you to extend the platform to make it achieve what you need so that you can spend more resources developing the value that is important to your customers instead of the pipes underneath.
Of course our solution cannot work for everyone but the companies that we have worked with thus far have told us that increased their application throughput by 8x compared to when they built backend themselves with frameworks like rails/django/node.