Author here. These ranges are typically wide because your compensation depends on your interview performance and perceived seniority/value add to the company.
There's no way to tease this out before you interview, except that if you're looking for compensation that's significantly above the top of the band, it might be hard to get. (A little above the top is possible, and sometimes a lot is possible too... that's where the negotiation comes in.)
I feel like it's not a great look to say "I don't know enough about the role to give you my salary expectations at this point" while also asking "but what is the salary range for this position, given you don't know enough about me".
This may sound quaint but I find that being forthcoming and asking the question you have works.
During the latest job search, I would just ask for a range and say myself that "obviously where I fall in the range depends on my candidacy, I won't hold you to it."
If they tell you the range is something like $120K to $150K, it tells you what kind of seniority they are looking for - whether they know it or not - and how much they value people of that profile. If they tell you it's like $150K to $750K - then you know they are really wide open to range of experience and impact. Someone may say that a $600K wide range is meaningless but I don't think it is. If you're more junior you can count on being towards the left but still know they can afford to give you a bit more if they like you, and if you're very senior you can recognize that they have room for someone like you and have an appetite to pay. You'd be totally self-unaware to go into the process hoping for $750 and then landing at $150 but that's more on you.
So I am fine asking for a broad range - it's way more meaningful than no range.
It is very helpful, the bottom of the range tells you almost everything you need to know. I don’t care if the top is $1B per year if I am willing to accept $200k in order to decide which jobs to apply.
I think that's true when you're on the more junior side of things. When you're more senior, you're more interested in the ceiling. the $200k may not be enough but if you know it goes up to say $500k - you can consider interviewing.
That's not "completely unhelpful" - if your current job is $99k/yr or $400k/yr it answers your "should I bother spending time interviewing here?" question quite nicely.
The fact that the range is 100k isn't that big of an impediment to utility.
It can be a valid range - I've seen plenty of postings (internal at least) where the the seniority is flexible. Also a flexible location could also lead to a big range depending if you are based in NYC versus Iowa...
Like, ok your range is $150-250k, fan-fucking-tastic, that’s completely unhelpful