Fun exercise, I went ahead and asked ChatGPT, here is what it had to say:

Prompt: what does ワープロ馬鹿 mean?

"ワープロ馬鹿" (waapuro baka) is a Japanese slang term that literally translates to "word processor idiot". It is used to refer to someone who is not proficient in handwriting kanji characters because they have become too reliant on word processing software and digital devices.

This term was commonly used in the past when computers and word processors were becoming more popular in Japan and many people were losing their ability to write kanji by hand. The term implies that people who rely too much on technology to write are lacking in basic writing skills and knowledge. However, the term is now considered outdated since the use of digital devices has become more prevalent in society.

Prompt: what is an equivalent term that would be used today?

Today, a more common term to describe someone who relies too much on digital devices and cannot write kanji by hand is "スマホ字 (sumaho-ji)". This term is derived from "sumaho" (smartphone) and "ji" (character), and it refers to people who are unable to write kanji characters by hand due to their heavy reliance on smartphones and other digital devices for communication and writing.

Other similar terms used to describe this phenomenon include "キーボード依存症 (kiiboodo ishizonshou)" which means "keyboard dependency syndrome" and "タッチペン馬鹿 (tatchipen baka)" which means "touch pen idiot". These terms reflect the increasing reliance on digital devices and the declining use of traditional writing methods in modern society.

スマホ字 seems completely made up, and google results for the others suggest entirely different meanings....

On the second and third try it came up with スマホ字バカ, which doesn't exist either.

When I asked entirely in Japanese, it insisted on キーボード依存症. The best it came up with after a while was 筆力低下, which literally means decline in ability to write, and doesn't seem to be used to describe this phenomenon, per Google search results.