Engagement is far from useless, but its equally far from being good enough to be called a level 72 skill. There's no "progression" in job evolution.
It's main use as a anti-platform death mitigator won't see nearly as much use appreciation at 72, as it would, if you got it at 40.
It has other uses for sure, a possible additional 150 potency every manafiction from well timed use, the ability to stay close to the party during restrictive mechanics and the ability to burn multiple OGCDs before the boss invulns without the long animation of Displacement.
Overall though its just too little too late. Its a QoL skill at its core and should be a core part of RDM decision making from the beginning.
The level 72 skill should focus on RDM's healing/defensive support side on the OGCD, in my opinion at least.