Just chiming in to give a recount of my own experience:
I never had any issues whatsoever with payments from itch.io in the past; in fact many of the previous transactions came through way faster than the 10-14 days they give as a rule of thumb. However this time it's different: payout was initiated on the 7th of March. I've waited patiently up until the status read "14 days ago" before I decided to contact support.
Side note: I routinely check all info on my profile out of habit, and about 3-5 days prior to contacting them, everything appeared to be in perfect order still (including tax information). And I'm not kidding: within mere minutes of sending my email, they replied, telling me my tax info was apparently expired or something. Of course I immediately went to check - lo and behold, it now read: "Invalid" and asked me to refile everything. I strongly suspect that the same person who read my email also kicked my info out of the system to make their claims look legitimate.
So I did that; actually had to do the tax interview twice because after the first take, it still showed up as "invalid" for no reason (trying to trick me, itch.io?)
Anyways, their reply also stated: "This process of manual validation typically takes 48 hours at the most" - that was about 46 hours ago at this point in time, and I have zero confidence whatsoever that I'll receive either payment or another response within that window. Heck, looking at y'alls reports of how long you've been waiting... I'm starting to think they're unable to pay and just won't admit it.
This is unacceptable and absolutely bordering on fraud. They are withholding money that isn't theirs, for which they definitely should be held accountable to the fullest extent. The lack of communication and unwillingness to act on the matter would almost warrant to collectively sue them, in my opinion.
I have earned this money; it is mine, they owe it to me - denying that without ever giving a valid explanation factually equals theft.
I still like itch.io as a platform (not taking into account the shady practices of whoever runs it) but this'll be the last time I trust them with anything. As soon as the currently pending transaction goes through, I'm switching payout mode for sure.
I'd rather deal with a little bit of extra paperwork than dealing with scam artists.