Yes there is a first and a last.
But the last is a job that only brings DPS to the group. Imagine if a Medic in FPS had access to better guns than a Soldier?
I'm curious, which jobs does everyone think should be top and bottom three and why? Or should they all just be perfectly equal across the board?

It's true that maintaining uptime and hitting positionals isn't that difficult but the fact is they exist for some jobs and don't for others, not everyone's going to play perfectly and I would assume that SE balances with that in mind. MCHs don't need strategies built around them to do well and they don't require party members to play well and make good use of buffs. Healing utility from dps also isn't really needed at all, rezzing is nice to see more of a fight the first time but you're going to have trouble getting enough dps if people are dying all the time.

Imo it makes sense for MCH to be relatively low on the charts. Maybe not this low but what do I know (spoiler: not much). It certainly would feel better if the jobs were within 500 dps of each other rather than 1000+ but I'll not pretend to understand what goes on at Squeenix or why they do things, I'm merely trying to be logical.

In early weeks, where DPS actually matters, Job choice can decide wether you will clear the content or not.
I really hate this argument. You know what else helps clear content? Not dying is a big one. Eating food, using potions, slotting (good) materia, getting better gear, doing your rotation better, taking less damage so healers can dps more, and so on. Hell even some world first groups would rather have better players using jobs they're more comfortable with over whatever's topping the charts. Playing better >>>>>>>> job choice.

In any scenario where playing a different job would have made the difference between a clear and a wipe there are without a doubt a number of other things that could be improved, things that will improve with more time and practice.

Since we're talking about the first few weeks here I would also argue that jobs which require more effort to pull higher numbers would take more time to reach those higher numbers, whether it be developing uptime strategies or learning where it's safe to greed or what have you, things MCH doesn't need to learn like other jobs.

obviously players in the game for years can easily reach the skill ceiling.
You would think.

There are all sorts of people in the world and they always manage to surprise me.