Typically IPFS pinning services use cloud providers such as AWS S3 to host the files you upload. So while those files are still technically part of a distributed network, they are effectively just hosted in a traditional centralized cloud storage manner (assuming they are not also pinned elsewhere). Filebase does not use AWS to store your data... it uses distributed storage networks such as sia. See sia.tech.

The nice thing about the URI ( for example, ipfs://bafkreicysg23kiwv34eg2d7qweipxwosdo2py4ldv42nbauguluen5v6am, ) is that it tells you what the content is, unambiguously, but you are not locked into any single system for storing or retrieving that data. That method could change over time, so you don't want to embed it in the blockchain.