Follow-up question. I understand how Richter Scale + depth could be useful, academically. But when communicating with the public, wouldn't it be easier to have a single number - rather than requiring the public to understand the relationship between two different quantities? Maybe: surface-equivalent Richter scale?

Of course transitioning to a new standard would be even more confusing for a while.

Edit: apparently there are many different scales in wide use already. https://en.wikipedia.org/wiki/Seismic_magnitude_scales