Computers are a tool. Because they are the new things it is hard to see that they are just tools, so I like to start with this related question: do hammers improve education? Lets look at that question first.
I have never seen a math teacher who I would trust with a hammer.
English (language) classes might have a paper mache hammer - one student made as a prop for a play and it has been hanging on the wall since.
Physics teachers need a cartoon oversized sized rubber hammer.
Shop class will have 60 different hammers, for some types there will be one for each student.
Art class will have a couple, and once in a while borrow a bunch from the shop class...
Now that our mindset is correct we can re-ask the question: are computers useful? The answer is what are you going to do with them.
Part of modern English (language) class is typing. Starting perhaps 3rd grade there should be regular streams of reports handed in electronically. As students get older much of the literature they need to read is available free on a computer and hard to find in paper form. Other than a caution about handwriting and spelling still being useful skills I expect to see a lot of computers in language classrooms. As the kids get older things like web pages will be added to English class. (web pages have more in common with journalism than computer science!)
When the kids get older I expect art to be done on a computer, but for elementary aged kids art with messy paints is better than the computer. (some professional artists find painting on a computer is better than real paint: it works the same way until you want to hit undo or need the paint to dry at a different speed - but that is for older kids)
Math is about reasoning through a problem. Computers running flashcards can be useful at times (single digit addition, subtraction, multiplication should be memorized), but ultimately computers are easily harmful to the goal of teaching reasoning. In fact real math problems the arithmetic is easy enough that not being able to do it is a sign you made a mistake.
Science is like math, except the real world is messy and so an equation solver is helpful. Most of the learning is actually before the point or writing up your report though, and not using a computer is an advantage as it forces you to think about how you will measure something.
Shop class (though this barely exists anymore - I think this is a great loss) should cover CNC and 3d printing.