Why not? Once a computer can learn at 1x speed (say one camera and one mic with which to observe the world), if it can indeed "learn" as fast as a human would, it sounds like all we need to do is throw more hardware at it at that point. And even if we couldn't, it could at least learn around the clock with no sleep. We can give it some specific task to solve and it could work tirelessly for years to solve it. Spin up one of these specialist bots for each tough problem we want solved.. and it'd still be beneficial because they like 10xPhD people without egos to get in the way or children to feed.

Point is, I think self-learning at any speed is huge and as soon as it's achieved, it'll explode quadratically even if the first few years are slow.