it is easy to explain, you are making your mind being exhausted by potencies and whatever the mathematical facts that you are trying to use to understand why bitcoin and almost all the other currencies are using decimals.

But you need to understand that it is not because Pitagoras or Einstein decided to create those decimals are the reason of why bitcoin has 10^8.

It is only because of terms of money, it works by the same way as the cents.

Tell me, if we all had to pay using bitcoins without decimals, we could only afford things who are over $15000 at the moment.

just use that logic.