That's a Japan thing and a legislative failure.

What normally happens in most countries is the law would say something vague like "digital means or devices such as floppy disks or equivalent".
Then the Executive makes and maintains the rules of application of that law according to the Hierarchy of Norms (things probably are organized differently in Common Law countries so I don't know the English term but the principle is the same), which dictates in more detail how the law is to be applied ("please use a web form, or a USB keys for legacy processes").

Sometimes the executive lags behind a bit but typically it's just a ministry making decisions within the margin of the law, so it's not too bad.