Their most sisyphean issue is the transaction locking. Imagine, 20 people trying to buy 19 trinkets, and you try to resolve transactions in a distributed DB, and two guys manage to buy the same thing in the exactly same nanosecond. The task is hard to tackle.

If you time-atomize the transaction, you get increase in minimal latency.

If you simply use a single server with very fast DB, you get reliability concerns.

With token ring locking, you get both.

And so on, so on, and on