Attributes and stat enhancements aren't useless, been plenty of testing that has proven this. Every game in existence that has an attribute system has a cap on stats in various factors, either:

1. At "Level 40" your STR will have a stat cap of +80 then you will notice diminishing returns beyond that because for the level, it's balanced around only a boost of around +80, so if you have 38 base STR +80 and you gain 300 additional damage to your skills, that's as high as the damage will go ignoring specific mob weaknesses.

Then you have the fact as you level the cap raises and the diminishing return cap raises as well.

or

2. You have an overall stat cap of +999 which the damage itself scales with and how you layout your skills (if a talent tree exists.)

The problem with XIV, is the base stats are way too high and not necissarily done so "for the future" because FFXI for example only has base stats of iirc 87 ignoring stat merits and the current cap is now 99, 10 years later, but every +10 stat you add gives you a noticable increase because the base stats are low, but in XIV, even with over +100 of a stat, you still barely notice an increase at times.

So the problem is not that a cap exist (every MMO in particular has stat and damage caps) its the fact they're all over the place if you do actual testing you realize this fairly quickly.