There are thousands of open questions here and they are bumped to the top sometimes. However the big part of them are abandoned so they will never be resolved unless the community vote for their closure (which is actually legitimate in the case the question does not comply the community rules).
Questions are only bumped by the Community bot when they are considered "unanswered". "Unanswered", in SE's terminology, means there are no upvoted answers. When the questions are bumped, the community is expected to upvote existing answers, or otherwise write a better answer if there are no satisfying answers. When there is at least 1 upvoted answer, the Community bot will stop bumping without needing the answer to be accepted.
There are also questions which are not properly managed like this one: cucumber java.lang.IllegalArgumentException: Not a file or directory:
The author here resolved his issue on his own but didn't mark the answer as correct. So, we have tons of the questions which will never be resolved and will be mixed by a community bot with the questions which obviously have higher "instant" value for the people bumping them up to the top.
This is quite an unfortunate event. Perhaps the user was new to Stack Exchange and they didn't know about accepting an answer, or they just thought that their answer is not the best. No problem with that.
However, there are already 3 upvoted answers, and it won't be bumped anymore (considered it already "resolved").
I'm suggesting you to discuss whether it makes sense to introduce a mechanism of consensus letting the community decide whether there is a correct answer provided for the question in the case the question author doesn't do it.
Acceptance doesn't indicate correctness. This is already stated in the help center:
Accepting an answer is not meant to be a definitive and final statement indicating that the question has now been answered perfectly. It simply means that the author received an answer that worked for him or her personally.
The tooltip on the checkmark also says:
The question owner accepted this as the best answer.
(emphasis mine)
Acceptance is always subjective to the OP, and OP is not forced to accept any answers (this is controversial, but it has been like this since the origin of Stack Overflow). This also means that the community shouldn't force the acceptance of a certain answer.
The conclusion is, the community can already decide if the answer is correct: upvote them!