AWS S3 buckets have a limit of 5gb/s access to a single bucket.

Unless that limitation has changed in the last couple of years; I can easily make a system beat that, if that's the requirement.. and ultimately it does come down to understanding requirements. :\

I think generally people forget that cloud is just computers too, it's really not anything special, and amazon/google/microsoft are solving the general case (and, doing so well, actually) but this comes at a high premium.