Questions that don't get answered can happen but may get answered over time.
The only way to try and get these kinds of questions answered is to promote them. This could be through social media, it could be back linking it on other forums, anything that draws attention to the question at hand.
Since this is a QA format, questions that fall off the front page are usually gone to those who are not looking. Questions get found by users looking specifically to answer questions or users who have a similar issue and are looking for a solution. They come across them either via Google (other search engines, sure, but Google is the highest by a longshot) or the site search engine.
Users who are looking to answer questions then need to decide if that specific question is something they're looking to spend time solving, explaining, and writing up. If they feel it's worth the effort then an answer is submitted.
Users who come across it via search either see it has no answer, maybe throw it an upvote and move on or hopefully solve the problem on their own and come back to submit how they got around the issue.
Getting answers to questions sometimes revolve around how common the question is or how much effort a random stranger wants to put into answering it.
Most of the questions linked in your post are ~2+ years old and all of the questions have less than 700 views. An average view count of ~431 which is not as high as it looks.