Do you really think blueberries wouldn't work? Highbush blueberry here in MI grows wild in old bogs/marshy areas where water often stands for weeks on end in the wet times of the year, and they seem to thrive. Old timers around here always called them "swamp huckleberries" even though they really aren't a true huckleberry.

My thought would be to bring in soil for a raised bed. Depending on what you want to grow 12-24 inches would really improve drainage on top.

Both great ideas- I should have been clearer.
I also tilled much more ground than this- that is slightly higher- and will put in raised beds everywhere else for blueberries etc.

This spot is so low it is squishy mid summer. I was going to plant alsike clover here as a "lawn". Alsike loves spots like this, and so do bees. But after tilling it just looks way too nice for a lawn!

Well, I can't think of many other edibles, especially fruits, that will grow in that condition. However, it sounds like a nice place for some kind of water feature, bog garden, "rain" garden, swale, etc. It definitely sounds too good to waste on lawn, which is fundamentally a drain on resources at this stage of the game.

I am mystified by the universal recommendations to use a well drained soil and avoid damp spots for fruit plants of species that will tolerate considerable periods of flooding in the wild. None would probably do you any good in Z6 though.

Muscadine grapes and pawpaws are obvious examples, and guavas are another when you consider the escaped reverted guavas in South Florida. Rabbiteye blueberries and mayhaws may be others, though I don't know the exact conditions of wild rabbiteyes other than in broad stream valleys, and don't recall whether mayhaws are recommended just for well drained soil.

One aspect that makes this all the more mystifying is that (except for guavas) these plants have only recently been selected and bred. They are still very close, literally just a few generations at very most, from their wild relatives. A good number are simply selected FROM the wild. They are not highly modified from wild plants.

I know the experts are not just knee-jerking: they specifically mention experience with root rots on muscadines and pawpaws (and perhaps the others). Yet I see wild muscadines and pawpaws flooded all the time, including occasions (several a decade) with substantial flooding for a week or more in the growing season, in cases when heavily laden with fruit, in cases with 2 feet of water, in rarer cases with 6 feet (after tropical depressions pass upstate). They seem to do fine. I am foraging the fruit a few weeks or month later.

What gives?

Here in MI there are bogs where people place planks between bits of solid ground, to go deep into the bog and pick blueberries. So I agree with Dennis. In case you have an interest in perennial edibles, rather than fruits... You could use ostrich ferns for fiddleheads (a shoot, not a fruit, but perennial, and it spreads), also a bog-side dweller, and you could put down rows of mushroom-injected logs, which you can use as stepping stones but that will also gift you with mushrooms (a fruit, quasi-perennial as a log lasts 3-5 years) a few times a year. Celery (annual) and watercress (reseeds, therefore perennial) also will do well at that location. Bamboo (I recommend psyllostachys nuda) will also shoot at about the same time as the fiddleheads. Its shoots are the best, but a pain to clean.
It spreads a lot, of course, though a 15 ft wide mowing strip will stop it, or a 1-ft deep barrier.

"flooded all the time"

The "all the time" was an unfortunate choice of idiom. I mean every year I see some flooding in areas with healthy muscadines and pawpaws, but not all year (not literally "all the time").