The assumption is wrong, you cannot spend single satoshis, at least not on-chain (dust limit)
In order to get round numbers when converting fiat currency (e.g. 1 cent = xxxx satoshis) you also need several digits.
The smallest practical denomination is maybe 1000-10000 satoshis
There is not even enough BTC for each millionaire to own one, so they are pretty rare - especially compared to other cryptos.
Look at it like this: Gold is rare. Yes there are trillions of atoms per gram, there is enough gold on the planet for each person to own a little gold dust. But it is still rare compared to iron, or silicon.
