personally I think this could be great as an over-the-wire format, rather than storage, since as you're pointing out it makes no difference in storage.

the biggest advantage is that it's super simple to encode and decode (simpler for your cpu than json, in fact!).

sending 1000s of events from a relay could save hundreds kilobytes of data (which is great for areas with bad internet, or phone connections), and plenty of cpu cycles on both the client and relay (i.e. better for older devices, and cheaper servers)!