A goot tip (something that I do) is to do a keyword search of the topic, read the relevant posts on the subject of choice, then decide if you want to reply somewhere or create a new topic!
That being said, sometimes a new post makes for some interesting new discussion and a refreshed view on things, whereby newer members feel they can still add input without the weight of many established member’s opinions looming above them!
Generally, though old members - i.e. myself and Metro - may get “frustrated” with the same old discussions a new thread can be interesting for newer members disinclined to hunt through the site. It does no harm after all and I prefer it to threadomancry