If Apollo is the interface, what is Reddit besides a JSON document store and object storage for media? Once Apollo is big enough (network effects, critical mass, whatevs), it could spin off of Reddit as the backend (Cloudflare R2 for objects, workers and KV for comments). You can even backfill from the numerous Reddit archives (Internet Archive, Pushshift, etc) out there.
(Apollo user with an interest in a distributed web platform)