... and a lot of people who consider joining the forum probably get discouraged from it by how difficult ZOS makes it to join the forum. With many other forums, you can just subscribe using an email and password, and you're in, but not this one.It makes sense to me that only a minority of players would visit the forum. I've played dozens of games, probably a few hundred, and I've signed up to forums for 4 games/series, plus 1 Discord channel. I only do it when there's a lot of things I want to ask or discuss about a game. If it's a one-off question I'm more likely to just search for an answer online or use a site I'm already on and hope someone knows the answer rather than seeking out a new community. Most games I just play and don't feel the need to talk about that much, especially with random people online.
I suspect most people are similar. It wouldn't surprise me if the majority of ESO players don't know this forum exists and a large chunk of those who do never look at it.
It's nice to have a place to discuss the game and get updates and additional info (especially things I wouldn't even know to look for) but it definitely shouldn't be considered a definitive representation of the whole playerbase.