The majority of summoner's 'free movement' GCD's are monopolized by it's opener and it's Bahamut period, the way it breaks out is at the most you have 2 or 3 extra casts that allow for free movement every minute, not much of a difference from Red Mage and the 2 enchanted Reprise's you can get off between your melee windows so your cool downs don't drift. And even though Phoenix movement isn't AS punishing as Bahamut, you still want to limit it as much as possible as the chances of losing Scarlet Flames out due to the Demi following you like a loss puppy is too high, and that loss isn't insignificant. Having played all 3 jobs in a raid setting I would rate their maneuverability as Red Mage > Summoner > Black Mage if you are trying to play them at their absolute peak. But even then I wouldn't consider the gap on any of them significant.
Scholar is the only healer that truly lacks movement at this point. I did white mage throughout all of Eden's Gate Savage and was surprised just how much the addition of the Afflatus spells really helped in moving around. Astrologian has always been quite mobile due to its shorter cast times, and a skilled one can move just as easily as Bard's could in Heavensward. And Lightspeed is still a thing. Scholar feels just as rooted as Black Mage, so it just becomes a party thing on which one they prioritize.
I'll just have to agree to disagree. Wither or not the best ones are too few, I hate anytime a class or hero based game starts balancing and making decisions on the more random PUG environment, it always ends up leading to either homogenization or dumbing down the class for the sake of those who can't work it out. Making the job less rooted isn't going to suddenly make those players better and less toxic. They still will stand too far away, they still won't come in for heals, they still will not learn mechanics, they still will shout at anyone who gets close to them even though they cancel a cast every 4 GCD's. And it should stay that way. That's how Black Mage should be at it's peak. It's skill comes not from it's rotation, but it's game sense. It's rewarding to learn a fight to the T and zoom all over the map and watch your numbers still blow by everyone else on a class that's supposed to have the agility of an oak tree.I'm going by 'most', not 'worst'. The good BLMs -- the ones who anticipate mechanics, heal points, team buff timings, and actually move in to be in range -- are far too few. Other jobs are often moving to hit the BLM's range. Also, a static group is a completely different animal. This thread is for the sake of reducing the random BLM's worries as well as the party's worries in a pick-up run.
Honey, I agree with you on the overall theory of your argument, but let's not gate keep here. Someone who is great on even an 'easier' job is still better then 98% of the population on this game, even if their take is wrong, there will always be room for amicable arguments. We don't have to be pricks about it.