If the game is getting harder then we will need dps metres. Official ones.

[HeyMcFly]

The stone, sky, sea dummy things are the dps meters- if you can kill it in time, with plenty of seconds to spare then you're good

[Absurdity]

The stone, sky, sea dummy things are the dps meters- if you can kill it in time, with plenty of seconds to spare then you're good

Except they can be wildly inconsistent and unreliable. They can sometimes be basically impossible to beat because they haven't been tuned correctly, it happened in the first Eden tier.
And they can potentially promote playing your job entirely wrong, since beating a training dummy in a very short timeframe is not the same as an actual bossfight.

[Sebazy]

The stone, sky, sea dummy things are the dps meters- if you can kill it in time, with plenty of seconds to spare then you're good

Also note Stone Sky Sea does nothing to help a group understand their buff window alignment or the current pressure on healer DPS (which can vary wildly).

That's before I touch on how it does nothing to help someone practice keeping their GCD rolling through movement and incoming mechanics.