This system is anti-social.
I routinely have times where a friend or group of friends needs help, or just one fill, or I might just feel like pushing buttons and helping out a PF... but I'm not welcome there, because the system will punish them for my presence by dramatically reducing loot if I already cleared.
The RNG protection from bad luck isn't enough.
I've been clearing through P7S in PF since Abyssos landed, 8 weeks in total, and won almost nothing. I still have 12 more weeks of P6S and 8 more weeks of P7S to get BiS for a single job if I don't start getting insanely lucky. My deep, deep frustrations with how badly RNG has screwed me this tier might not have any real relevance to the community at large, except...
Content that requires BiS is occasionally released before Savage unlocks.
At the time DSR launched I had barely managed to finish gearing a single job, depriving me entirely of options for it. You can make the argument that it's fine to not be geared for Savage, that 610 crafted and pentamelded is good enough, but this simply is not true of Ultimate.
Not only does this deprive players of the freedom to swap roles to reduce the sometimes hours long waits to fill, or to find groups to play with, but it can outright block people from even making the attempt. If the next ultimate lands a month from now and my drop luck hasn't turned around, I literally may not have enough HP to survive some of the mechanics in there on my main, much less consider a role swap. Nor would most groups even allow me to join in the first place, and they'd be right not to. "Wait until you have the gear" is not an acceptable response to this problem, as there are going to be far fewer people approaching any given fight after the release patch and it becomes much more time consuming to attempt, even without considering concerns of wanting to attempt the fight before gear scaling makes it easier.
ASS(S) might fall in this category too, but I admittedly have no clue how tight the DPS checks are just yet since I'm still working on the last boss of normal. I sure as hell hope not, because that would force me to quit playing with my friends since I had to pick up an off-job for our group to work and would be a liability to them, and have no ability to do anything about it in this system.
Finally, this system doesn't respect our time.
If I want to be able to play with friends at my leisure, and engage with current content and do it on multiple jobs, there is exactly one way to accomplish that. I have to make one or more alts, level them to 90 on potentially multiple jobs, and grind out additional tomes for each one weekly. This is completely contrary to the stated design goals of the dev team.
Please give us some more options for horizontal progression, stop punishing groups for having people that already cleared in them, and improve RNG protection.