Sure, the format is slow and somewhat complex, but then it seems like all the places are devoid of non-immediate conversations.
Companies are moving to the Slack, informal groups to the Discord. I've been using IRC for years and I still love it but with recent adoption of Slack it seems everyone wants to push all the communication there and I don't think it works. It's hard to search for stuff (usually it takes me 3-4 queries to find thing _I know_ is there) and then it's in lengthy conversational format that takes a bit of time to replay. You might lose window of opportunity to provide important info just because you aren't present at the moment and since Slack is perceived as a low impact tool, those conversations can happen in late evening hours.
And yet all the places that (in my opinion) were better to have more fruitful, thoughtful and searchable conversations are slowly winding down. Newsgroup are long dead, mailing lists are perceived as archaic, forums are closing down one by one. It might be me, but I start to get feeling that even on StackOverflow conversations aren't what they used to be. Only e-mail is left - in some places at least, because some organization start to have "why send an e-mail while you could send Slack message". Thankfully those organization usually bless users with capability of installing Slack on their private phones /s
Too bad Google Wave didn't pick up.