It’s better

I like to use the regular one. I find ink storm just fun to use.

79 is better than 47. Just saying. I mean, TriSplash is better than Storm tho. If you look at it, 47 is more focused on Support/Backline/Defense while 79 is more Attacker/Offense/Frontline focused

I’m talking about splashdown by the way

Ye. at least we have Splatoon 2 speed. Also, the radius nerf is because of this:
Because the TriSplash charges quicker, the fists of ink have less time to charge a harder hit for a larger impact radius. So, the more time TriSplash takes to wind up, the wider the radius due to more potential energy being stored over a longer period of time. It makes you vulnerable for longer, though.
Nutshell Form: More Potential Energy = Larger Radius

Bro is using what he learned in school

Yes but it makes sense. What if we could control how long it charges for a larger radius in the future?