In addition to other points, you can consider the arbitrary inflation of fiat as a sort of fee. When you get fiat from anyone, you can not assume the availabil

In addition to other points, you can consider the arbitrary inflation of fiat as a sort of fee. When you get fiat from anyone, you can not assume the availability of the same currency tomorrow. The state controlling it can arbitrarily create more whenever they please. That is the dominant source of inflation in fiat currencies, whereas in btc and other cryptocurrencies the velocity of funds becomes the influencer in that same regard. That happens in fiat too, but is overwhelmed by the prevalence of unpredictable money printing. The point is that with a sufficiently entrenched cryptocurrency, that volatility due to money entering or leaving the market (ie, buy some btc as an investment and sit on it) is drastically reduced (and the volatile availability of funds combined with the speculation gives bitcoin its unpredictable exchange rates) you eliminate the most prevalent forms of unpredictability from your money - since with crytocurrencies, the algorithm makes the monetary base very predictable, and if you had a currency at a "good" inflation rate generating a lot of monetary velocity the frequency of funds leaving the system for an extended time (besides lost wallets) would be even more negligible. That inherent overhead of unpredictability in fiat is a natural "fee" that everyone has to subconsciously consider what evaluating transactions using such currencies.