I have been following this space for really long time. I think closest competitor is Airplane.dev [1]. One of the most difficult thing to sell as a sales person is to sell an open ended workflow and UI engine and ask me to segment and prospect customers. It is not that you cant sell it, it is just too broad even for your customers to figure out a usecase, because theres always a specific tool to solve the usecase. For instance, stripe refund is one most common usecase posted by all of these platform, but there are actual tools that just does stripe refund and they solve it in depth. You can argue these tools are value for money but then if it involves build time, in long run it becomes expensive. Retool is actually captured the market really well. It is basically become the verb in the internal tool market, it is hard to compete with that even as an opensource project.
[1] https://airplane.dev