>>None of the cryptos that exist today can even function as an effective "buying stuff" currency because they are all deflationary, not just in exchange rates and short term speculation but in how they all mine at fixed / declining rates to finite limits.

This graph is evidence against that theory:

https://bitinfocharts.com/comparison/transactions-btc-eth.ht...

Note that Bitcoin's tx volume hasn't been able to increase since the blockchain reached its 1 MB limit. Otherwise it would have seen continued growth like Ethereum.