IRC is almost always logged, and if you need to log things yourself, you can use a bouncer or set up a server.
Not to say that Discord isnt deeply flawed in many respects, like client weight/resource usage, abysmal search (in server but especially DMs, coarse and clunky permissions systems, audit situation? and the very fact that using animated emojis will cost you 5 dollars per month is just stealing sweets from children, and their absolutely sickening boost (ponzi?) scheme...
No, the reason for that is more likely that all the darn generation-Z kids are deathly afraid (and therefore pretend to be deeply contemptuous) of any old-fashioned technology created by Unix greybeards.
(Now geroffmylawn.)