>This is how we got to a gold standard over some thousands of years.

We started with gift based economies where people keep track of favors in their head and after that ancient Egypt introduced a grain standard which did the exact opposite of holding value and it worked for thousands of years and encouraged long term investments like the pyramids as there is no point in making the rest of the economy wait eternally.

The Roman empire ran the first silver/gold growth pyramid scheme which forces it to conquer more and more territory to mine more silver and gold as they fail to circulate throughout the economy and lead to pointless economic stagnation. Egypt fell victim to this overexpansion and once the Romans ran out of easy territory to capture, they couldn't mine enough silver to pay their soldiers, forcing them to reduce the silver content of their coins. This is especially problematic if those soldiers are foreign mercenaries who are former refugees driven off their home by the Huns. Since there are plenty of privately wealthy people with gold and silver, they try their hand at playing Caesar and hire their own army, only to get killed by another self proclaimed Caesar or by their own men if they run out of money. Some Caesars tried to impose price controls by threatening capital punishment instead, with little success.

What we are looking at are two thousand failed years of permanent money. Madmen trying to do the same thing over and over again with the same expected outcome.

Honestly your whole argument has a pretty huge flaw and that one has nothing to do with store of value or medium of exchange but rather with a property that any successful medium of exchange must have. A medium of exchange doesn't need a high velocity or be a good store of value, those can be desirable in some contexts but they miss the essence of what it means to be money.

Money is an asset whose primary property is to be highly liquid. Liquidity is the ability to trade one asset for another. Money is effectively a joker. Money that is widely accepted is more liquid than money that isn't. Money that is difficult to handle and transport is less liquid than money that is compact and lightweight. Money that needs to be weighed and verified is less liquid than stamped coins or bank notes of fixed denominations.

Government approved money that can be used to pay taxes or loans is more liquid than privately issued money where people have to voluntarily agree to accept the currency.

If you build your money on a commodity, that commodity will need to be versatile and either be the foundation of your economy or have a wide variety of uses.

Not even money itself is perfectly liquid. A soda vending machine may not accept large bank notes or credit cards, meanwhile self checkout may only take credit cards and no cash.

These properties are independent of whether the currency retains its value or has a high velocity. Of course, extreme shocks in either of these properties may ruin liquidity but most currencies tend to limp along even with 20% inflation which according to you should be enough to ruin liquidity and make everyone and their dog switch to gold but again, dollars are more liquid than gold so people prefer those.