Well, I don't mean to imply that binary files are inherently impossible to handle using a decentralized system. In fact, I have some PDFs and PNGs in my git rep

Well, I don't mean to imply that binary files are inherently impossible to handle using a decentralized system. In fact, I have some PDFs and PNGs in my git repository, and git has managed not to make a mess of them. But I still think binary files are difficult for distributed systems to support well. Distributed systems rely on allowing people to (in effect) create multiple versions of the same file, and then merge them all together later. But it's very rare that binary files are mergeable! And if the file can't be merged, the distributed approach won't work. People will step on one another's changes by accident, and people will have to redo work. The usual solution is simply not to allow multiple versions to exist: enforce some kind of locking system, so that each editor has to commit their changes before the next one can have a go. But now you need some centralized place to store the locking information...