This post is mainly for newbies, but I guess older members can take the advice too.
Don't just create a topic for creating's sake; create it because you want to learn/know something, or you're passing on information or news.
Most times, I see topics by lower-ranking members about something they don't understand, and there will be answers and solutions to that problem in the comments, but there is no follow-up reply by the OP. It leaves me wondering if the person actually reads the replies to their posts. When you read the replies, you will learn more or have more questions.
I think most of the people you think they created this threads are not really here to learn, they intentionally creat those thread to farm merits or it could be that they created that thread to keep that account lively or active.
Some may also creat this thread to gain knowledge and may have learnt what they needed but always have that habits of not replying.
This is a discussion forum, and the only way you can learn is by discussing. Just dropping a topic and not reading to see what people are discussing on the topic doesn't make sense. Make use of the Telegram bot or any other ways to keep track of replies to your topics and posts, interact, and not just drop topics and forget about them.
I think the last part you made mentioned of, is one of the reason why they don't come back which is not having a telegram bot notifier that will keep them in touch with new replies. I had same experience of not using telegram bot, and I was missing Alot untill I later activated it and now I can get feedback of any mention, quotes, merit an any other notification.