Not $518B in the next year, they plan "to spend $518 billion on cloud, computing and infrastructure obligations in coming years" (number of years unspecified)
Google, Amazon, Oracle, Microsoft, Meta, SpaceX, and tons of other startups are spending trillions on data centers, but everyone is renting them out. They aren't renting them to each other (and paying the extra overhead when they have their own servers).
That leaves basically just OpenAI and Anthropic on the hook to pay for everything BEFORE the GPU half of it depreciates away, but they are busy cutting prices to compete with Chinese models which runs counter to their need to increase prices to fulfill their obligations.