You forgot that instead of fixing PUP's longevity issues and DPS spread when using the caster automaton, the devs allowed roundabouts to game mechanics like ADA to exist.
*puts on Scholar's Mortarboard* For those of you who don't know what ADA is, it stands for Activate, Dismiss, Activate. People who used caster automatons would activate their automaton, have it cast a spell, then dismiss it and use activate again to summon the 'maton, provided the automaton's HP was 100%. What this did is get around the internal cooldown the automaton had for casting spells, and if I'm not mistaken, it also reset the amount of MP the automaton had every time it was resummoned. You could technically get it to cast spells back to back using that method.
The only high parses I've ever seen of PUPs involved ADA. See my above point.
After years of the job being treated like garbage post-penta nerf. One does not undo the other. There's a reason the "Ryuu-san the DRG has been waiting for 6 hours for a party invite" joke came about.
I'll disagree with you here. DRG in order to get access to healing breaths (lol) required them subbing WHM, RDM, BLM, BLU or SCH, which more likely than not you were not going to sub for events. You were coming /WAR for double attack and berserk, or /SAM for meditate and the ability to solo a lv3 skillchain (I'll concede that you also needed Spirit Surge).and DRG wasn't about only DPS either. But then again, no other job even came close to the healing efficiency a DRG could put out (6mp for 600~800hp at any moment in time, and 6mp for 1200~1400hp healed every couple minutes), and while still being able to outparse most DPS.