The reason why fiat loses value over time is that the people controlling it funnel the value into their own pockets at the expense of everyone else (what a surprise).
The people controlling it are not inflating the currency by putting it into their pockets, which would effectively deflate the currency by removing it from circulation. Inflation is a direct factor of government spending and government money creation which subverts the discovery and valuation driven by supply and demand of new credit.
https://www.aier.org/wp-content/uploads/2013/11/EEB198405-REVISED1993.pdf
You're also using dollar valuation to define the value of bitcoin, which you say is not storing value, but creating it. Yet if you're to define it by what actually is the accepted definition, it is in fact a store of value:
A store of value is essentially an asset, commodity, or currency that can be saved, retrieved, and exchanged in the future without deteriorating in value. In other words, to enter this category, the item acquired should, over time, either be worth the same or more.
By your logic, every classical art that has been outperforming gold is a Bitcoin System of Trust or functioning as one, despite the obvious implications of counterfeits.
You should have stuck with "Define Value" as then you obviously wouldn't be demonstrably wrong regardless of how ridiculous you pigeonhole the subject, as its not objectively defined like a Store of Value is.
Sophistry is tantamount to intellectual assault, do you enjoy contorting easily understood ideas into absurdity and nonsense to the detriment of truth and common sense?