

You can’t just round to the nearest 5¢. Round up, and you end up pissing people off for overcharging them. Round down, and you end up losing money on every sale, which adds up over time with hundreds or thousands of transactions a day.
The grocery stores around me put up signs a month ago asking people to pay in exact change when using cash due to the penny shortage. Without stores able to get more pennies from the banks, this will become a problem in months, not years.

You could mount a cloud storage device as a pagefile, which would be a convoluted way to “download more RAM”!
Yes, there are some significant technical hurdles to jump through and it’d be impossibly slow, but it can be done!