Now that's a great question!
I think everyone's busy with life and such, to me it looks like some person doesn't even bother posting in a thread if it was made by a person they don't know or don't like in particular and this is why when a newbie tries to post their mod or mods no one will bother to play it or nobody bothers to give a feedback or anything and these days nobody is willing to post anything useful to the public, it's rare when a code tutorial post is made, it's rare to see a texture pack posted, people try to keep their stuff to themselves it seems. The community looks open for everyone but as I see it isn't, because it's torn into pieces, there's the group who's around in ages, who seem to get along well, there's the group of newcomers no one seems to care about and at last but not least there's the ECWolf group as well, each group is different than the other two. The first group don't seem to care about the group of newcomers and basically just ignore them in most parts while the ECWolf group is just that they have their own ways and methods of how to mod Wolf3D. As I said the community's gate looks open, but for newcomers it's basically closed because no one cares about them or about their mods and this is something that could kill the last spark in someone and kill their passion of modding and they will leave, so there's no way to actually fit in the group and then there's the ECWolf group which is to be honest should be a part of the ZDoom community rather than Wolf3D because of all the scripting, the modding tools and how stuff work. I believe this community doesn't work like a community anymore. This is just the way I see things, I mod Wolf3D since 2012, but joined DHW in middle 2017 and posted my mod there, nobody made any post with a single word, no feedbacks, nothing at all. People say the more mod you make the better, I don't see it that way, I prefer quality over quantity, I could release a mod in each month without caring about their quality, but it wouldn't be me, I want to put out something that will catch people's attention, something that will make them play it and return to play it again and again, something that will turn into a classic, you know what I mean, but since no one give their feedbacks, be it positive or negative, as long as it is constructive then I could "evolve" and do what people want to see, but this just doesn't happen at all. Everyone is acting like a "lone wolf" these days. Once again this is how I see things!
About the discord server, most active members there left the server or got banned, because of extreme disputes that there's more Doom members than Wolfers and the place is basically turning into a mixed bag or mostly a doom server. As I am one of those who got banned I do not know how life goes on on there, but as I have heard about it all the time that this is the case there, then I believe it's quiet there as well then.
The community looks dead most of the times that's for sure, but as long as people care about Wolf3D and have some interest about it, it's not dead yet.
EDIT: Actually for instance, I remember when some of us tried to tell Luke Skywalker to reconsider his posting tendencies and he immediately started to ramble about that he is around for ages so he knows how things go in the community and the newcommers should shut their mouth because their opinions are just jealousy, pointless, unintelligent and just straight up pieces of trash.