In fact, given so many cases are missed (bloodstream antibody tests don't catch those with T-cell responses, and mucosal antibodies aren't detected by those tests, either) I would not be surprised if those with complications are a minority (of extreme clinical importance, mind you) of the total cases.
My point is not much as to downplay the seriousness of these side effects, but rather that we have become more aware of them due to "information overload", because many other diseases can have these complications. IOW, this is not a magic disease (sometimes the press almost paints SARS-CoV-2 as something out of this world...).