I disagree, simply. There's so many novel UX patterns in websites and apps, it's impossible that you've got a clear idea of what is or isn't a dark pattern in every circumstance.

Uber Eats used to have a "$0" option for tipping, but removed it, it's no longer clear if you're going to be giving a tip or not, but if you don't click anything you don't actually give a tip. Is that a dark pattern? I think so, because the UX makes it seem like you have to select something, and that no isn't an option. But it's not hard to argue in the negative, since doing nothing will not take money from you.

You seem to give a pretty good reason why it's a dark pattern, and a pretty flimsy one for why it's not. I think it's not as ambiguous as you say.

I didn't realize this was going to be such a controversial take. It's possible you think there's a clear definition because you haven't seen examples of what some industries think is ethical. I'm trying to pick relatable examples but clearly not doing a great job. Again, I tend not to think these things are ethical, but I'm not the ethics police, so the fact that one person thinks it's ethical and one person does not means it must be blurry.

I feel pretty strongly that tracking cookies are evil, but the entire ad-tech industry did not think that was a dark-pattern.

I feel pretty strongly that GDPR "accept all or leave site" dialogs are a dark pattern, but the EU is happy with that implementation.

I would also love to point out that "dark-pattern" is still a blossoming terminology, there's no definitive body of law or ethics that describes what is and isn't a dark pattern.

The "accept all or leave" has recently been ruled illegal because the law requires "free and informed consent". Refusing service without consent isn't a free choice to the user.

Similar for Google that went the "you can disable cookies in your browser" way, I doubt that will survive a lawsuit in the coming years.