Blockchain has taken a weird path. It started with Bitcoin offering something genuinely new - a Byzantine fault-tolerant mechanism for decentralized value exchange without trusted intermediaries. But the industry has drifted toward "web3" hype where the technology often isn't necessary.
Companies pick tech stacks for all sorts of reasons beyond technical merit - vendor relationships, development velocity, legacy system compatibility, and UX considerations all factor into these decisions.
Truth is, most blockchain companies today are solving problems that could be handled just fine with traditional databases and APIs. The industry is shifting toward abstraction layers that hide the consensus mechanisms anyway, focusing on user experience instead.
The project mentioned probably doesn't actually need a blockchain backend for what it's doing, except maybe for tradable collectibles on an ERC standard.