Again this argument is pretty pointless without numbers.
Here's a study that concludes that 5% of all youth football players age 5-14 sustain a concussion each season:
https://www.jpeds.com/article/S0022-3476(18)31586-5/fulltext
I tried to find the same for soccer, and some studies said it was a similar number, but they were reporting concussions as a percentage of injuries, not as a percentage of all players.
Also, concussions have increased over the years, but most articles say that's due to the increased emphasis on them and diagnostic ability.
Regardless of how they compare to soccer, let's take the 5% number on face value. Your kid has a 1 in 20 chance of sustaining a traumatic brain injury that could severely affect his neurological development given that < 14 years old is the worst time to get these injuries.
Should tackle football then be allowed? Should parents be given the ability to make that decision for their kid? Keep in mind that as cliche as it is, some parents are living vicariously through their kids or have unrealistic expectations that they'll play in the NFL some day, and are willing to take that 5% risk to keep deluding themselves.
I actually don't know what to think in this situation (I only have a daughter so as of now it's moot). I'd have to think about it more. 5% chance seems pretty high though.
If you think 5% is small enough that the benefits of tackle football outweigh that risk, what number would be too high? 80%? 99%? Just curious.