Pretty sure that COVID showed the exact opposite. Our brains evolved in the meatspace and won't be happy anywhere else.
Even the success of remote work shows this. People want to avoid the office (and the commute) to get more time with friends, family, and their hobbies. The internet is most successful when it helps people live the life they want in the meatspace, not when it tries to replace it.
In my experience, there is usually some percentage of people that archive whatever channels they use. Sometimes they will put them up on a website.
There's also nothing stopping anyone from doing that, and it's quite easy. I've always just had irssi running on some server that archives everything and I ssh into the server when I want to chat.
While it is true that many public IRC channels publish logs on the web, I cannot remember the last time such a log ever showed up in my google results. It virtually never happens. If somebody's primary concern with discord is search engine indexing (rather than discord being a for-profit company, not a federated service? rather than the discord desktop app spying on the other programs you run? rather than discord requiring most people to hand over their phone number to use the service?) then surely they have the precise same beef with IRC if they stop to think about it.
Honestly, not being indexed by google is the least offensive aspect of discord. For most people these days I think it is actually a benefit. Tides are changing, common people are becoming apprehensive about their words being immortalized in some ledger easily accessible to the public which future employers will be able to trawl through for disqualifying out-of-context remarks. The objective in such chat rooms like discord and IRC is to make ephemeral connections to other people and discuss things in the moment, not to build up a semi-permanent corpus of information for the benefit of people googling things in the future.
No different than an office workspace no?