I think this system is much easier to understand from the beginning. I required essentially no explanations: interpreting probabilities as some number between 0 and 1 seems more intuitive than betting odds and lines, which I still don't quite grasp.

Agreed. This system of floating prices can also be easier to understand when studying depth-of-order-books, or moving in-and-out of positions before an event resolves. Those are essential for peer-to-peer prediction markets, but often not offered by pure betting services.

(As an assist to people familiar to other systems, PredictIt could offer a display of effective-odds as an option.)