The secondary reason is timing. And it aligns how funny things happen when the value of $1/1£/1€ in a currency drops below a certain threshold.
A $1 cheeseburger becomes $2. Then $3.50, followed by $5.50.
Instead of the population doing math in fractions of a whole unit - a dollar/euro/etc, suddenly they are doing math without decimals to interpret somethings cost/cheapness.
It’s a huge shock to the brain when this happens as the difference between $0.25 and $.50, and then $1 and $2 are the same %, yet perceived as different.
The USD, Euro, Pound, AUD, NZD, etc are all recently breakaway from decimals (cents) mattering. Cents have become rounding units and insignificant.