I feel like this is something that has been a common occurrence since personal computers started entering the workplace, but people who accomplish it usually follow up by expanding the scope of their job. Personally, I know someone who has "automated her work" using Excel at several jobs, to the point that she spent a few days per month doing the entire job of the person she replaced. These were jobs that anyone could have automated any time in the previous 10-15 years, and were automated at other companies she worked at, but at several companies she was the first to do it.
In software development, I "automated my job" many times in the old days in the sense that I was given a task that I was expected to do in a brute-force manner over several weeks, but I solved it by spending a few days cleaning and structuring the data and then writing a script. Now people are less and less surprised by the ability to solve problems with programming, so instead of handing out tasks like that, they are more likely to ask a product manager to design a new capability for internal tooling.
I haven't personally encountered somebody who used automation to coast in a job. The intersection between people who can achieve this technically and the people who can achieve it socially is probably pretty small. (If I automated my job, I would have a hard time keeping my mouth shut about it. My Excel friend is a squeaky-clean go-getter and would not be able to resist taking on extra work.) I understand the choice, though.