The idea of “zero” was well known, but the actual representation of zero as a number had to be invented. We use Arabic numerals because their numbering system was so much easier to use and calculate with than the Roman or Greek numbering systems that used letters for numbers and quantities. The place holder numeral “zero” was indeed a great invention........
This is not true at all. The numeral 0 originated as a place holder in positional number notation, and while this ultimately suggests that it ought to be treated as a number itself, its status as a place holder by no means requires it.
In fact, it's easy to see that zero as a number still has a shaky status in popular thinking. For example, the "Cash Back" screen on a card reader at a pay station in a store will have, e.g. $40, $20, $10, NO ... the last meaning, "NO, I don't want cash back", so there isn't any NUMBER of dollars I'm getting back.
I saw the same thing in my childrens' grade school class room, years ago. The class had a small chart showing the number of children in the class having birthdays in each month. Months with no birthdays were left blank ( or perhaps marked N/A ?? ) ... There was no NUMBER of birthdays for that month.
The efficient representation is what was invented, not zero.