The purpose has slided.

IRC was an instant/synchronous chat protocol. We had newsgroup/web forums for unsynychronous chat/dicussions.

The likes of slack, and later discord, had the idea of merging sync and unsync discussion to provide both.

In the end slack/discord/teams ended up being jack of all trades/master of none.

Yes the backlog is saved automatically but for most of them the search is slow and borderline unusable and it ends up being much more difficult to search for information than using google with the site:yourwebforum.example.org option.

in exactly the same way as how the post I responded to depends on your definition of purpose, a point it seems I illustrated successfully

as for your snide, obviously wrong comment at the end, it's not worth a substantial response

Sorry if it comes across as snide but I really do wish it were different, I do wish IRC were less niche. But when all of its defenders start their HN comments with "I", it's difficult to see IRC supporters ever looking beyond the needs of the niche they exist in as individuals.