This is such a naive statement. I love FFXIV, I agree it could use some more content, but let's not kid ourselves...
Dungeons in FFXIV are about the same level of faceroll as ezmode dungeons in WoW. I would put the new speedrun (less than 18 minutes) of AK post-patch as challenging as a gold challenge mode in WoW. Except WoW has like 8 challenge modes for 5man, whereas AK is just one... speedrunning CM and WP are complete 1-tank 1-heal faceroll.
There is FAR less trash in ffxiv than in most of the older raids in WoW, as far as time is concerned. At least that trash had some interesting things that may or may not drop.
Quite frankly the only remotely challenging content for an organized group is turn 5, and that is simply a massive gear and overtuned issue at the moment. I would argue your average heroic boss on WoW, especially in older expansions, is considerably more challenging than anything in FFXIV outside of turn 5, maybe turn 4 and pug HM titan.
FFXIV is an okay difficulty, but could use a lot more challenging content.