Number of bosses isn't a meaningful statistic (Also, people are getting it wrong, as ADS is also in turn 1; technically turn 2 is actually 2-5 mini boss fights in addition to the actual main boss- only a couple of the MC bosses are anywhere on the order of any of Coil's bosses)

FFXIV's dungeons don't feel as substantial only because they don't have anywhere near the amount of trash mobs that Wow dungeons have. Major encounters are a larger portion of the dungeon experience.