Bjj doesn't need effective striking to get submissions off. They use more of a smother approach. And then positional dominance.
But they do use striking, yes? I don't limit striking to jabs or low kicks. Any use of the hands or legs to make contact or to distract or mislead I consider a strike. This is due some of the techniques that Jow Ga uses. So while I may do a punch to set up a grappling opportunity, if my opponent doesn't get out of the way of this punch then it will land for real. Best way I can describe is is that I throw a punch that will cause you to move backwards which is what I really want you to do. But I'm equally happy if you don't move backwards and get smashed in the face. When my technique fails, you don't move backwards but you get hit in the face. If my technique works, then you'll move backwards and I'll get to set up the technique I was going for., but you don't get hit in the face. So to me that is a strike. We have a softer one that can be used as an ear slap or to thread my hand between your guard. In either scenario my target is your ear.
So that's where I'm coming from when I think of strikes. If the purpose of your strike is tap me on the head to distract me, then to me that is a strike. So while BJJ doesn't have the boxer strike damage. They are still effective in making the opponent move the way that you need them to move in order to advance or grapple. Is it needed all the time? Of course not but the fact that it exists gives me a direction to look towards. If I want to grab someone then I want do it when they least expected it so that they are least able to defend against it.
Aikido has to win the striking. There is no dynamic I have seen for when an Aikido guy is getting mauled. Unlike BJJ which sort of works off that
To be honest most of the Aikido sparring that I've seen, seems to abandon striking. They wade in with the intent to grab a wrist. Which is like me telling you. I'm going to grab your wrist and put you in a wrist lock, then I proceed and only try to get the wrist lock. There's no need for you to defend against anything else because you by my focus that I'm only going to do 1 thing.
If I take my kung fu approach then I would tell you that I'm going to embarrass you and put you in a wrist lock and make you tap out. Then while you are looking for my wrist lock I will punch you in your face. Then I will tell you that I will still go for the wrist lock. I would feit a punch to your face, go for your hand and then I'll kick you in your gut. Will I eventually go for the wristlock. Only if you aren't looking for it. You will have bragging rights that I couldn't put you in a wrist lock, but I will have bragging rights that I did a lot of kung fu on you. But the moment you forget about your wrist, I will try to take it. But Aikido doesn't do that. right off the back you know they want to grab your wrist, so you defend your wrist and they will fail.
Now if gpseymour step into the ring with me or you and nailed us with combos, and kicks that make us forget our wrist, then he'll probably get our wrist.