The half-remembered storage system I pulled those numbers from had records ~100G in size, so a 10^-7 loss is 1 loss event per year, per exabyte of data. A loss event is just “at least one bit in the record cannot be read within a certain deadline”.

Durability is a knob. If you have enough data, or turn the knob too far in the direction of durability, you will simply bankrupt yourself or maybe drown your service in latency. It makes sense that you would have storage services that provide different levels of durability.