Nobody needs them, its a matter of making your game more enjoyable to play. You sound mad jealous tbh :3
Also there are no addons that actually makes fights themselves easier, merely some things like skill rotations. And even those are far from used by everyone on PC.
Other addons assists with targeting. Did you know that its entirely possible to make macros ingame letting you heal somebody by mousing over their name in party list without changing target?
Furthermore, did you know there is an addon that does the same, but without the games inherent skill queing problem? Square needs to up their. But I digress. You give somebody tools to assist them and they will use those tools.
And those who are too poor to afford said tools don't get to use them, and will inevitably try to make their lack of something useful a point of pride because denial.