It's a rather great looking + feeling platform and the blog post is nice too, but I find the arguments against federation quite weak and have diminished hope for Discuit's popularity based on it not supporting it.
It may still be a bit away from a tipping point and the UX may not be 100% finished, but to me Lemmy looks like the clear favorite for a platform one can use today. If you're compatible with it you automatically get its content, which is a valuable commodity for kick-starting right now.