Or a series of files with numbers that go up and a data structure tracking their dependencies. Git and others might use Merkle Trees but they're not even necessary. Good, but not necessary. Lot of ways to represent these basic concepts with so many tradeoffs.
That's why it's exciting when people break away from the crowd dictating specific approaches and start asking themselves questions about alternative techniques. :)
So git basically. Maybe instead of blockchain technology they could call it version control tech.