Having access to the technology is a pretty important thing, IMO. This isn't 1980 when personal computers were a rarity. Being computer illiterate is almost as bad as being actually illiterate.
There are also several things that computers can do that even good teachers cannot do. Computer-guided instruction allows the student to go at their own pace, rather than be held behind or left behind. You don't want to lose either of these groups. Students who fall behind tend to drop out, and bored students are, if anything even worse. Computer-guided instruction may also allow for a student to wander off the beaten track to follow a particular interest. Instead of just studying when Einstein developed his theory of relativity, the student can follow the theory itself.
We broke up school into discreet subjects because that's a good method for one-to-many instruction. But learning is rarely so segmented. A few hours of clicking through Wikipedia is often better than a couple of weeks of ordinary classroom instruction.
With a well-designed computer-aided library of knowledge you could cram 50 kids into a room with one well-rounded and competent teacher without too much trouble. Going this route would radically change the way people think about education. It would, I believe, even be cheaper than our current warehouse-style, time-clocked factory schooling methods. But it would anger the teachers' unions, the textbook publishers, the thousands of people employed to service the status quo, and most of all politicians who like being in control of piles of money.