Let's compare recreational judoka/bjj'er/boxer who trains 3h-week (there are thousands of them) with recreational aikidoka then.
First, what situation do you have in mind?
Look. O Sensei was not primarily interested in self defense. I don't think there's any serious dispute over that.
But "not designed for self defense" is not the same as "not useful for self defense." After all, some pretty serious martial artists passed through in the old days. If O Sensei had not been extremely capable, no one would have cared what he had to say and history would remember him as just another crazy Japanese mystic.
You can decide whether aikido is "designed" for self defense by appealing to history, but to decide whether it's useful for self defense you really need to explain what kind of situation you have in mind.
Which no one, so far, has yet done.
Again, combat sports are not self defense. Strike-breaking is not self defense. Self defense has some overlap with fighting, but self defense and fighting are not the same thing.