Asking "what have you tried?" suggests that the answer to the question will lead to the answer to the problem.
But the person seeking help already knows what they have tried, and they don't have an answer.
So in the absolute best case, it's a useless question, you're just trying to get them to rubber duck it. In a less-than-great case, it'll be taken as a suggestion that they need your guidance in basic critical thinking and troubleshooting.
In my view, the very limited potential upside (successful Socratic rubber ducking) is not worth the significant potential downside (insulting them by suggesting they already have the answer, they're just not smart enough to see it).
> In my view, the very limited potential upside (successful Socratic rubber ducking)
It depends on the situation - if you're not familiar with the person asking, and you're talking with them one-on-one, it can be a chance for them to establish their dignity so you can triage their request properly.
If I'm looking after a shopping website and someone tells me they can't put things in their basket, I might usually start by asking with some pretty basic questions.
By giving them a chance to tell me they can't put things in their basket on pages X and Y but can on Z, and it only happens when using Firefox, and that they've tested with multiple accounts, these browser versions and OSes, with and without plugins/ad blockers, and they've got confirmation from several other people - probably I'm going to skip asking them to clear their cookies and I'll launch straight into reproducing it myself.
On the other hand, if I'm looking after a shopping website with clumsy warehouse staff and a customer tells me they ordered two widgets and only received one, probably I don't need any more info from the customer - and resolving the problem rather than batting it back to the customer would be good customer service.
People are not equal in (sub-(sub-))domain experience. And we all can be distracted or dumb sometimes. Consider how powerful rubber ducking is : it works even when you're not talking to another person ! (And you might not think about doing it in a stressful situation.)
It just needs to be done tactfully. And in case it was a stupid mistake, defuse the ego issues by telling an anecdote about how you've made a similar one. (It's even helpful if it was a dangerous mistake : telling how you got punished, but the world didn't end.)
The answer to that question is quite likely to lead to the answer to the problem. There usually are a multitude of different possible causes, and the answer to "what have you tried?" eliminate many of them, and the second valuable thing is that when they say what exactly happened when they tried that thing (other than that "it didn't help"), you may have different conclusions from that observation that they did.
But the person seeking help already knows what they have tried, and they don't have an answer.
So in the absolute best case, it's a useless question, you're just trying to get them to rubber duck it. In a less-than-great case, it'll be taken as a suggestion that they need your guidance in basic critical thinking and troubleshooting.
In my view, the very limited potential upside (successful Socratic rubber ducking) is not worth the significant potential downside (insulting them by suggesting they already have the answer, they're just not smart enough to see it).