I've been connecting the dots in video/bandwidth delivery.
While I was digging up an additional link, it appears Cloudflare R2 allows no egress fees.
https://www.cloudflare.com/developer-platform/r2/
10GB free to host, no egress fees.
Combined with a cloudflare worker, it seems reasonable that the object storage could be managed.
Now your castle is in someone else's kingdom. And in Cloudflare's kingdom, always be ready to get an email: "pay us $150,000 in 24 hours or we cancel your service"