It may turn out that it isn’t necessarily the hard hits that are the problem, but just a lot of small hits over many plays that do the damage.
If you want to look at another similar sport, say Rugby, they don't use padds. I don't know if Rugby has a suicide problem, but, they also don't play on astro turff or against 350 lineman.
I think the small hits are exactly the problem...and a lot of these players have been taking small hits since they were playing football in pads since they were 5-6 years old.
My son played a year of football when he was maybe 9 or 10 years old. Got his only potential “concussion” in a scrimmage. It was a clean hit by a bigger kid. He wasn’t trying to crack his helmet but accidentally did. My son got up and claims he saw stars and didn’t remember his name for a couple plays and also forgot to tell the coach because he wanted to stay in the game since he wasn’t a starter.
I guess my point is that there are a lot of kids who are taking little unreported head shots really early in life, and I truly wonder if we’re starting our kids in organized football (i.e. pads and helmets) too early in their lives.
I think when I was a kid they didn’t really start tackle with pads until high school or junior high. We played tackle without pads but you didn’t lead with your head because it would hurt. Luckily stiff arms only hurt the neck...and only temporarily.