While Discord does some things right in the community platform space, I don't think its a suitable replacement for Reddit. One of the biggest issues with Discord is how the content posted into a community is lost into the abyss. The discoverability of content on the platform is basically non existent.
Lots of the Reddit alternatives, including Discord, seem to be missing the core idea of what Reddit really is (a community of communities). I think first and foremost it's the community aspect of Reddit that makes it appealing.
I've been working on a community platform called Sociables that combines the feature set of Discord with the discussion boards and discoverability of Reddit. It's like a Discord/Reddit/Patreon hybrid where the posts are search engine indexable. We've built a place to monetarily incentivize ownership over the communities created on the platform as it feels like the people curating the communities should be rewarded for the work that they do.