I tried to read about Willow, but could never make heads or tails of it [1]. It seems to be a hierarchical key value store with a bunch of extra fields for timestamps and cryptographic tokens, but it's woefully short on working examples. Even the recent Rust library [2] is effectively a bunch of abstract classes with implementations that just throw errors.
I could make a quip about the state of European tech sophistication, but I'll let it pass with a polite smile.
[0] https://willowprotocol.org/earthstar/spec/
[1] https://willowprotocol.org/specs/data-model/index.html#data_...
[2] https://github.com/earthstar-project/willow-rs/tree/main