People come to TSE to ask a visa type of question and then disappear. Sometimes they show up weeks or months later, sometimes not. Sometimes they take the question to another site and I have seen it happen enough times to believe it's standard OP behaviour.
Sometimes the OP shotguns their question into a dozen sites and loses track of where they are. They show up the next day and ask the same question because they didn't keep notes of where they asked. Visa questions are always EMOTIVE and do not have the same trajectory as someone asking (for example) how to reach the base camp at Mount Everest.
The abandon rate in TSE is appalling. I don't know how many answers get the 'acceptance' check mark, but I bet it's the lowest in the whole SO framework.
The TSE ecosystem rewards good answers by community votes and that's that. OP abandonment behaviour is part of WHAT IS and I don't see any sort of software mechanism changing it.
In some cases, this is fine, but sometimes it would be helpful to know
if the answers actually helped the user in question.
It may seem presumptive, but we already know it worked out OK. Or it would have worked out OK if they actually used the answer.
For example, if someone asked for a clarification on how to answer
certain questions on the form for UK visit visas, and got an answer,
it could be helpful to know if it worked out for them in the end.
Again, you have to trust that they got good info. Whether they used it or not or whether another site gave a different answer they liked more or whether the OP decided not to fill out the form at all... All of those things are irrelevant. We did the best we could, the community voted, and end of story.
Perhaps the powers that be could implement a system that sends an
email out to users periodically reminding them to chose an answer (at
the least) and maybe even to leave feedback on how helpful/accurate
the advice actually was.
I respectfully disagree. We are not Amazon sending out follow-up emails every two seconds. Visa questions are EMOTIVE and personal; postmortems are unnecessarily intrusive.
On the other side, we should be a whole lot more aggressive in marking duplicates.