Of course, there will be many individual categories of jobs in which employment will be falling. This doesn’t mean unemployment will rise, of course, as there may be other categories in which employment is rising and sometimes there are entirely new categories of jobs.
You raise an interesting example about word-processors. Word-processing allows individual pieces of work to be completed more efficiently, so you might think it leads to an improvement in administrative efficiency — but it’s not that simple.
One effect of word-processing is that many managers are now expected to go without secretaries, leaving them to rely on their own two-finger typing skills.
Another effect may be that firms and government departments are able to demand far more paperwork than they used to demand when only typewriters were available.
Overall, is administration conducted more efficiently than it used to be when we only had typewriters? There may be fewer ‘clerical’ jobs, but overall, are there fewer people employed in administration?