Yeah this forum is "old" but for me it's broke in like an old pair of shoes. I'm here for the comments and find the clutter of pictures, inline ads, automatic clickable text, etc. in more modern forums to be a distraction. Sometimes I have to look around to find the content of the post. I view this site with signatures off for that same reason. I don't need to keep seeing your truck & camper when I'm here to read your comments.
Posting pictures is an issue and there are countless newbies commenting on how they couldn't figure out how to upload a picture of their problem. In end, most get it figured out or at least post a link to their picture.
Focused conversation in specific user forums or pages can be great but much of what I've learned over the years wouldn't be found there. RV's of all types have so much in common so the larger the group the better.
I suspect user attitudes and moderation are bigger drivers of whether people stay or go, not just that "it's old looking". I could be wrong.