Variance in player skill is hurting FFXIV's itemization design.

[Kaurie]

Raid groups are, but content done through party finder and duty finder is usually synced to a minimum ilvl. Having higher ilvl gear does actually help, but you're still synced down to the upper most bounds of that level range.

You're only synced for old content, not things like Expert Roulette.

You are inexperienced in WoW, so I don't blame you.
In WoW there is a power difference of 2x between a heroic geared and a mythic geared raider alone.
That difference easily climbs up to 4x if you look at a non raider because not only does he have lower item level, he also is denied proper trinkets and set bonuses.

Yes raiders should have a power advantage. After all they do beat the hardest content and put in a lot of effort.
I feel that the difference FF provides is more than enough. There is no need to go to ridiculous levels like in WoW.

No I get that, and I said one can add set bonuses without making you do 2x more damage.