I'm very capable and confident, but I find that as soon as I can't do any one thing that other people perceive as easy, I get lumped in with the spoilt people who are wilfully useless and have been spoonfed everything their entire lives. Despite my life having been exceptionally hard to the point where I now have multiple disabilities as a result.
So I tend to sympathise with the helpless when it's a single incident or there's any possibility whatsoever that there's an underlying cause.
And it is up to the other party/parties to keep an open mind about that. My autism, for example, was undiagnosed for decades, but before diagnosis, back when I had no idea why I found some "simple" things so difficult, I was no less autistic, and had no less of a valid reason. The same would apply with any disability/neurodivergence, and they are very, very common.
And of course it's fine to not hire someone, or not pursue a friendship/relationship with someone, because they find specific things that are needed for it difficult, whatever the reason. It's only discriminatory [ethically, I don't know about legality in relation to employment] if the task is not actually necessary to do the job or if you're assuming someone won't be able to do it based on a diagnosis rather than on their record so far.
So I reserve judgement on people's helplessness until a) I've seen enough of their behaviour to know it's a very frequent thing with them b) they've shown that they really don't care about the effects of it on other people and c) I am absolutely sure they're indulging in it or doing it on purpose. And getting to the stage where I'm certain of those things is fairly rare.
Some people really are entitled dicks who expect others to do everything for them. But with such people, their "helplessness" is usually the least of your worries, because they'll turn aggressive and/or manipulative at the drop of a hat, engage in dishonesty, theft, anything like that. Because they have no integrity. I save my real negative feelings for them.