High deceleration is consistent with a collision.
Or at least collision avoidance late in the game. If you’re regularly needing to jam on your brakes to not get in accidents then the insurance company figures you’re probably not paying enough attention and missing other opportunities to avoid collision less “abruptly”, which means eventually you’re going to be too late, so your rates go up because they “know” you’re getting in an accident soon.
Insurance is all about playing the odds, the more of your behavior they know the more they know about your odds, the more they can charge accordingly. If you’re a nice boring safe driver like my grandfather was it’s the system for you, if you’re emotionally incapable of not speeding when you get behind the wheel like me...