They wanted network effects because ChatGPT was sorely lacking any.
I actually thought the Sora app was promising at launch, at least on paper, but it seems like they failed to keep people's attention long term. With the failure of Sora i don't think they have good options left.
I generated a fair number of videos with Sora, and used a handful of those and edited them outside of Sora for a couple of short TikTok videos.
Never once did I bother to browse videos made by others on Sora itself. I wonder if anyone did.