A man walks up to a construction site foreman in the street.
He says "This is outrageous! If it wasn't for your digger, ten men with shovels could be doing that job!"
The foreman replies "And if it wasn't for your shovels, 100 men with teaspoons could be doing this job."
Computers are good at anything whereby outcomes can be defined in un-ambiguous objective terms, many of today's jobs are indeed easily measurable in entirely objective terms because they are wholly prescriptive - for example, a lot of clerical jobs are all about administration and following rules so it's easy to imagine a scenario where all of those are replaced entirely by automated processes. However, this completely ignores the fact that humans need to be involved in the first place before the automated process can ever exist because they're the ones who invent the rules.
Automation has been happening for a long time and usually resulted in better efficiency, accuracy, reliability, safety, cost-saving and human assistance but has never managed to replace humans altogether - the humans have simply moved from being the ones who are doing the work to those who create, control, maintain and monitor the automated systems. Fewer humans are needed to control an automated system, but that just means we can increase productivity by having the same number of humans being able to get a lot more done by delegating all the real work to the automated system.
Of course, we could easily imagine some kind of dystopian future where an AI becomes so smart that it replaces all human leadership, control and decision making, but I can't really imagine humans would either want or accept such a scenario - one thing we know is absolutely true about humanity is that people desire control (at least over their own lives if nothing else), so barring the Skynet/Terminator scenario, humanity itself is always going to be making sure that it is in control of its creations, with computers merely doing the work as well as providing input/feedback which help its controller/leader make better-informed decisions.
Realistically I'd imagine humans are likely to be increasingly involved in jobs based in the process of creating and maintaining automated systems as well as analysing the information made available by those systems to make decisions. For example, the construction site foreman of the future could still exist, except s/he is more likely to be an engineer and architect who takes the time to understand what needs to be built, monitors the construction systems in case something needs to be adapted, knowing how to modify and program the system so that they can get the job done properly and on time.