Well sure, they are both firmly in Gen X and as such I assume they kind of didn't know what to do with millennial SJW culture that emerged throughout the course of the series. A LOT happened/changed from 2011 to 2018, trying to keep up with it while simultaneously making comedy about it that also wasn't going to get them in trouble was quite the task, I'm sure. I agree that it kind of fell off in the later seasons, but I always attributed that to the fact that hipster culture (which is what the show was originally meant to parody) had basically died off by that point.* Hard to parody something once it stops being relevant, so they basically just coasted on the existing characters by giving them actual storylines instead of skits. Not nearly as funny that way.
*I saw Foals on tour this year (surprisingly good, though the frontman has a total dadbod which was weirdly comforting and funny) and I don't think I've seen that many man buns, skinny jeans, graphic tees, and ray bans since the pre-Trump era. The fact that I realized that look is now the exception, not the rule, of what you see at concerts made me realize just how far behind us hipster culture is.