> Without the intention to start a flame war, those under (lets say) 30 have a

Sure, but the attention span (jole alert) of a zoomer is 150 characters or whatever the Twitter limit is nowadays, so do they really need email for that? BTW I am using a webmail client, because I have the feeling that, and we have been pushing it in the corporate side for a while now, that emails are either one-to-one, one-to-few or multicast tools as we've seen newcomers struggle (even those of my own age above 30 who have not been involved in projects before) with this way of communication, so I have adapted to that workflow style.

So let's sum-up (from my perspective),

arguing what is better or not is pointless,

reality is what it is, the platforms used by young newcomers (where I believe we want to recruit talent from users to contributors in that demographic) are mainly IM based, for the forums, Reddit is slowly taking over (I am not cheering, I am just saying) , what our objective should be is to identify talent, turn them into contributors and find a communication platform that will work for silver surfers, OGs, and zoomers... it is a challenge, but if we won't do it, eventually our contributors population is going to age and well...

...you hear that from your politicians whenever they talk about pension reform where that leads to... unlike pension systems we probably won't have the luxury of highly increased productivity from automation, as we already are highly automated...

So the challenge here is as I see it:
a) identifying talent on channels many of us don't like to use, I myself am fine with Discord and Reddit, others may be comfortable with Telegram style IM, TBH in my days of XMPP we used it just for 1:1 IMs and I plan to continue doing so, besides Signal is better for that anyway

b) turning them into contributors

c) agreeing on a set of tools and policies that will empower all demographics to be *somewhat* comfortable and productive at the same time, I just feel that the differences in working styles among these demographics is so wide, that one forcing the other to adapt "their way" is not feasible anymore for growing projects... young people come to OSS for experience, with Discord we give them the feel of Slack - which frankly will probably be something they will be using at their day-job after they finish studies (or who know what will be the new killer app in 5 years), that is the reality, I miss IRC as much as the other guy, but times have changed...

For instance when it comes to mailing lists, I think we will have more success in that younger demographic if we also explain the way web interface for mailing-lists such as https://lists.opensuse.org/archives/list/project@lists.opensuse.org/ can be used... because of the way e-mail is perceived these days as I aforementioned...

For me open-source has always been about freedom to innovate, and ability to learn and gain experience, grow, including experience on how to effectively work within a larger team... I will (have) adopt(ed) just fine, but younger folks may have trouble with it initially, and it would be a shame to "push them away" just because of that...