I know Discord is popular, but I've tried about 3 dozen servers on a ton of hobby topics (linux , raspberry pi, golang, various games, politics) and I've found the caliber of conversation to be very poor. Nothing like forums, stack exchange or even reddit (especially pre-2012) in terms of topic focus, support quality, creativity, technicality. Convos tend to be banal, cliche, monoculture.

I would love to hear a testimony from someone who finds their Discord servers to be edifying or uplifting. What worked?

It excels for small communities, groups of friends and the like. My IRC channel migrated because it's user friendly, embeds images, and voice chat is a breeze.