Good thread, but the conclusion is missing the point.

Commodity monies have been a thing in the past. The commodity usually occupies the base layer of the hierarchical money pyramid. Actual currency – what people use to buy and sell things – emerges on subordinate layers. https://twitter.com/smdiehl/status/1384568528813035522

And these subordinate layers tend to be credit-based, backed (to a variable extent) by the type of money instrument that is above them in the money pyramid (i.e. at a higher layer).

Looking at history, there is little reason to believe that a synthetic commodity like $BTC could not take the role of base layer money – or at least as part of the ultimate collateral pool that constitutes the base layer – in a distant future.

In that sense, what's the base layer of the current $USD monetary system?

It's not Fed reserves and notes (cash). It's US treasuries that back the former.