Better that kids play with toy guns than real ones.
OP, honestly, guns have been favorite toys with children, not just boys, for many many decades. I remember when I was a little girl, my brother and I got “secret agent guns” for Christmas. Mine was a “radio” that unfolded into a gun when you pushed a 'secret" button. My brother’s was a camera. Oh, my, we had so much fun with those guns!!
Frankly, I’m thrilled that 70% of the toys are guns! These are the kind of toys that require a crowd, or at least a few other kids, to be fun to play with. It’s no fun playing with a toy gun by yourself! They’re SOCIAL toys that help kids to become involved with other kids and learn social skills.
OP, I’ll bet you a quarter that if studies have been done, they would conclude that children who grow up playing shooting games with toy guns never or seldom go on to commit violent acts with guns, while those children who do not get involved with other children in social activities including various gun games are the ones who end up committing violent crimes either as children/teens or when they are grown up.
So many kids don’t play with a group of kids anymore in free play. There are a lot of organized activities for children, especially sports, and I’m not criticizing that. But I do miss those days when all the neighborhood kids would get together and organize a war, or a secret agent society, or a space invasion, or a cops and criminals scenario.
It was so much fun!!! When I think back on it, it was quite complex play and involved a lot of organizational skills. We would spend hours setting up the scene and assigning roles (robber, murderer, cop, cop, detective, another robber, informer, etc.) and coming up with various rules (“Not allowed to run into your house to escape being killed, because our mothers will get mad at us for messing up the house and make us stop the game”). Then we would spend even more hours ranging around the neighborhood hunting each other down and trying to be the last one standing!
There were complex rules about when someone was actually considered “dead” and no longer in the game. Often, fierce arguments developed as to whether someone had truly been killed by the toy gun, and amazingly, we kids usually managed to sort out the various points and counterpoints and arrive at a mutually-acceptable conclusion about whether someone had been killed and was out of the game and had to sit out and wait for all the other kids to be killed, too.
Being killed was fun, too. We would drag out the death scene for as long as anyone watched us. When all the other kids got bored and walked away, we would cut out the drama and just fall on the ground and croak.
OP, my theory is that these shooting games help children to deal with their inner fears about being killed or losing their loved ones to death.
Anyway, I wouldn’t worry about it if I were you. It’s always been this way. If you actually watch children play, you’ll realize that they can be shooting each other one minute, and then all cuddling kittens the next minute.