The immersion argument is being used for... Justifying button removals? Good thing you can't see it lol... To many buttons is clutter. Sure. So is having a dirty hud. Here's my un-intentional immerse hud for how I play Samurai.
As you can see... I have barely anything because I just don't need to see anything. Un-intentionally it's pretty immersive. No less buttons needed though, I just memorized it. Was taught to me by mentors when I was still new to the game, although the Samurai weren't mentors they were just... lets call them " Overzealous-Optimizers " who yelled at me about not fighting your hud you're fighting the fight stop fighting your hud, leading to this minimalistic take to see mechanics better.
You could say if you want immersion for Samurai (
although not applicable to say Jobs with procs ) you could just memorize your job better to not need to look at as many buttons. With Kaiten removal, I went as far as playing without anything pressing Scr-Lck while screen-sharing fights to showcase mechanics even better for players who want to see how I on Sam handle mechanics in the hopes it helps them understand the fights.
So the immersion argument... to justify less buttons? seems a bit wishy-washy.