Based on their website, they solve the following problems:
- a central schema registery. Even if that's something you actually want, it's not a problem that requires $93M to solve, or a commercial company to operate
- communicating schema changes primarily via human-oriented sources like handwritten documentation on emails. I mean sure, if you are a masochist (or a sufficiently inefficient org), you might do just that. The rest of us here in the 21st century can check the schema into a Git repo instead.
- schema drift on the client end. Tough, this is what happens when you write software. Adding a third party won't help here.
- dependency management. For APIs? I cannot imagine a single case where that would help and your API isn't already a monstrosity.