Using a whole number for the smallest unit doesn’t mean you can’t name groups in useful ways. We have hundreds, thousands, millions as useful notation, even if we don’t give them specific group names.
Ultimately, it is easiest to say ten thousand safecoin than nought point zero, zero, zero, zero, zero one Bitcoin. Ofc, we can give the smallest unit a name like satoshi, but only enthusiasts know what one is or how many there are to a bitcoin (IMO).
Looking at it another way, a pound is a name we give to one hundred pennies. We often use K to refer to thousands of pounds (e.g 10k).
We can work both sides of a decimal, but whole numbers are easier to articulate, IMO. From a data size perspective, it makes little difference either - you need the same accuracy stored.