ELI5: How are the current dungeons hard?

[Arohk]

ELI5: as they reduced reaction times for mechanics, they expose the problems FFXIV's godawful netcode forces on players.

Nothing has changed in reaction time, it is the exact same as it has always been, people just need to pay attention to what the boss does and his cast bar, instead of waiting for a telegraph on the floor.

when a boss casts an ability for 3-5 seconds, you can't tell me there is not enough time to react.