That's my point though, using haga to sack 3 sen means u gain a 1 250 Potency oGCD and another 5 kenki for another at the expense of 8 gcds, where as if the boss hadn't jumped away for a cutscene u could midare for 640, there's more to it such as the calculation between an unbuffed midare and reduced when the boss does become hittable again but having to hagakure for downtime is intrinsically bad when other jobs like NIN can rebuff and get all their mudras back before downtime is over (in that particular 40+ sec downtime example) and, for example BLM can just hold on Xenos indefinitely and umbral soul to remain buffed assuming no cutscene, a point which becomes apparent when u look at aDPS, which SAM tends to lead on when there is sustained uptime and is generally the 1 good thing SAM is good for.
DSR - You can see BLM destroys SAM at the top end due to the aforementioned point of them being able to remained "buffed" and SAM needing a target to do so. Yes for the most part most SAMs will outperform BLM on aDPS but look at the gap for absolute best.
P6S
increasing damage wont increase uptake if the job is awkward to play in a piece of content, people who aren't die hards of the job will just go to a more fluid job.