It probably could be stated as a fact that "interesting" questions get more interest, answers and votes, while the "common" ones receive less attention on CV. I recently noticed that it happens (not so rarely) that this kind of "boring" questions are more susceptible to receive a low quality or even plainly wrong answers. This can happen in any thread, however what I noticed is that in such cases from time to time such answers get accepted, upvoted and not downvoted even if they are not correct. What can we do as a community about it? The up/down-voting mechanisms are not working if some threads are ignored, but on another hand there is too many questions to review all of them.
I'll frame this more widely in these terms: people here may readily disagree with (a) someone else's upvote or (b) the OP's acceptance of an answer.
Clearing (b) out of the way: An OP's acceptance of an answer is their exercise of their privilege. In principle, they are free to accept an answer they find helpful and need pay absolutely no attention to the votes and comments of other members or even the merits of other answers. I quite often find the answers accepted to be bizarre choices. Sometimes it can just be an early answer, or an answer that the OP wanted to hear for reasons that are not always good. But I don't usually find it helpful, or regard it as polite, to challenge an acceptance as wrong-headed, nor does that seem typical behaviour on this forum. (In some other forums, Meta seems awash with complaints on Why was this answer accepted?, and so forth.)
In all cases, you can and should record your dissent by
- voting in the other direction
- commenting on weaknesses or errors in answers
- posting your own answers that are, in your view, more correct, constructive or cogent.
I can't judge on your impressions that there is a particular problem with certain kinds of threads. Which questions are classified as "interesting", "common" or "boring" is too difficult to discuss. The definitions are tautological (interesting questions ... attract more interest) or too personal to be important, or for useful discussion the criteria need to be made explicit. More crucially, you don't give any examples of threads where you think our mechanisms are not working.
Many threads here on Meta highlight that we have a long tail of fairly poor questions. The biggest single reason appears to be that statistics attracts a large number of users who are unable or unwilling to put a lot of effort into learning statistics! What else is new? So, many questions are very confused or insoluble and it's often the case that despite discussions they don't become clearer or more soluble. But I am not clear that you are identifying a new or different problem.
As well as, or instead of, taking any of the actions @NickCox has discussed, we can flag or vote to close the common questions as duplicates (preferably soon after they're asked), thus ensuring they're linked to a good answer.