Getting an item noticed on HN is now largely pot luck. It is correlated with quality, but it's also correlated with time of day, day of the week, number of current readers, and it's still got a huge component of luck. If you don't get four or five upvotes in the first 30 to 90 minutes, it sinks without trace.
In part this is because of the huge volume. In part the volume is because the focus is as wide as it always was, but the audience has increased enormously.
Many potential solutions have been discussed, but in general, no one has produced a convincing analysis accompanied by concrete solutions that will clearly work.
Currently it's a case of - live with it.