Instant Support?

Why do many of the Open Source projects offer support/help via chat services like Discord ?

Honestly, it's a dogs breakfast (aka mess).  It's mostly a linear chat; people join, ask a question, and expect an immediate response. Is that really possible? Shouldn't we be managing expectation better?

The question may get answered, or just scroll off the screen (never to be answered) as more support chat happens.  People replying to a question don't use the Reply feature, resulting in a long, disjointed list of somewhat unconnected messages.

What happened to support forums?  No one expects an instant response.  The results are then searchable in the future too.