I myself don't visit server's website unless it has game download link that is not posted here or the link here is outdated and there is note directing you to a website. Once I do visit the game's website, I can appreciate if it has nice spiffy appearance but usually there is no reason to return there at later times even when it does have some changing content.
That panel window in the game launcher requires a website to exist if some live content (beyond showing just a static image) is to be displayed in it because the content if fed from it? I don't play servers lately but recall some that had this panel even scrollable and with links to change page. Probably only useful for patch info and server news display. Personally I would find it too onerous to visit the game's website just to check on this info.
Sometimes I click on the ingame bulletin board found next to SZ but that usually has a static message that is hardly ever changed for the life of the server. Had a dream how it would open a large panel window in game with live website content, maybe even a forum to post in. No idea if that would be possible to implement.
You can say, why bother when you can open a discord or a website outside the game, some folks may even have second monitor and keep an eye on the game while posting on discord... but ingame panel would lead to a much better game experience.
Also on discord you likely get many pple posting who didn't even fire up their game client that day or even who stopped playing the server but find the discord chat a good way to spend some time on anyway, filling it with inane chat exchanges. If you had them chatting ingame, at least that would keep up your 'user count' statistic.
I plain dislike discord as such regardless of the chat, it has a disorienting interface and dumb looks, dumb bots and dumb icons, pestering 'system' notices and really everything about it is esthetically unappealing.