Crypto Shower Thoughts

You ever have an idea hit you in the head like a shovel in the shower?  Well I did this morning. I am sure this thought has been had by many before me so I doubt I am breaking new ground with my random shower epiphany.  So my thought was as follows.  What if a company like say, Amazon, Google and maybe Walmart, created and controlled their own cryptocurrency?  They ran an exchange and set and maintained exchange rates for this currency to be used on their products and services.  Running it in full compliance with all governmental laws, tax codes and statutes.  What would the effects on the other decentralized currencies?  These currencies would have some sense of a backup value, like a fiat, but still like in the crypto space.  Not just any company could do this, it would have to be companies like the ones that I listed, that have revenues that are equivalent to GDP's of small countries.  This would give them the ability to exert massive influence and control over exchange rates and market supply of their currency.

If Amazon told us that their Kindle Fire tablet was $89 or 50 "Cryptozonians" (that is my name of the Amazon currency), and no matter what they held exchange rate between the two currencies through market supply, interest rates (staking), and other forms of market control, would that have a stabilizing influence over the market?  If a company(ies) like that did something like this, offering us multiple routes of easy exchange for tangible assets and goods, would that provide the market with a means to regulate itself?

I know there are a mountain of ethical issues that would have to be overcome as well as issues with these companies acting as almost independent reserve banks, but it was just a shower thought.